diff --git a/tools/aapt/AaptXml.cpp b/tools/aapt/AaptXml.cpp
index b04a55d91b9c2..6801a4ec73259 100644
--- a/tools/aapt/AaptXml.cpp
+++ b/tools/aapt/AaptXml.cpp
@@ -99,24 +99,40 @@ String8 getResolvedAttribute(const ResTable& resTable, const ResXMLTree& tree,
     if (idx < 0) {
         return String8();
     }
+
     Res_value value;
-    if (tree.getAttributeValue(idx, &value) != NO_ERROR) {
-        if (value.dataType == Res_value::TYPE_STRING) {
-            size_t len;
-            const char16_t* str = tree.getAttributeStringValue(idx, &len);
-            return str ? String8(str, len) : String8();
-        }
-        resTable.resolveReference(&value, 0);
-        if (value.dataType != Res_value::TYPE_STRING) {
-            if (outError != NULL) {
-                *outError = "attribute is not a string value";
-            }
-            return String8();
+    if (tree.getAttributeValue(idx, &value) == BAD_TYPE) {
+        if (outError != NULL) {
+            *outError = "attribute value is corrupt";
         }
+        return String8();
     }
+
+    // Check if the string is inline in the XML.
+    if (value.dataType == Res_value::TYPE_STRING) {
+        size_t len;
+        const char16_t* str = tree.getAttributeStringValue(idx, &len);
+        return str ? String8(str, len) : String8();
+    }
+
+    // Resolve the reference if there is one.
+    ssize_t block = resTable.resolveReference(&value, 0);
+    if (block < 0) {
+        if (outError != NULL) {
+            *outError = "attribute value reference does not exist";
+        }
+        return String8();
+    }
+
+    if (value.dataType != Res_value::TYPE_STRING) {
+        if (outError != NULL) {
+            *outError = "attribute is not a string value";
+        }
+        return String8();
+    }
+
     size_t len;
-    const Res_value* value2 = &value;
-    const char16_t* str = resTable.valueToString(value2, 0, NULL, &len);
+    const char16_t* str = resTable.valueToString(&value, static_cast<size_t>(block), NULL, &len);
     return str ? String8(str, len) : String8();
 }
 
diff --git a/tools/aapt2/Android.bp b/tools/aapt2/Android.bp
index 14d05fdf6ee8b..2ae2e496f25d1 100644
--- a/tools/aapt2/Android.bp
+++ b/tools/aapt2/Android.bp
@@ -92,7 +92,9 @@ cc_library_host_static {
         "flatten/XmlFlattener.cpp",
         "io/BigBufferStreams.cpp",
         "io/File.cpp",
+        "io/FileInputStream.cpp",
         "io/FileSystem.cpp",
+        "io/StringInputStream.cpp",
         "io/Util.cpp",
         "io/ZipArchive.cpp",
         "link/AutoVersioner.cpp",
@@ -140,7 +142,8 @@ cc_library_host_static {
         "xml/XmlDom.cpp",
         "xml/XmlPullParser.cpp",
         "xml/XmlUtil.cpp",
-        "Format.proto",
+        "Resources.proto",
+        "ResourcesInternal.proto",
     ],
     proto: {
         export_proto_headers: true,
@@ -164,6 +167,7 @@ cc_library_host_shared {
 cc_test_host {
     name: "aapt2_tests",
     srcs: [
+        "test/Builders.cpp",
         "test/Common.cpp",
         "**/*_test.cpp",
     ],
diff --git a/tools/aapt2/ConfigDescription.cpp b/tools/aapt2/ConfigDescription.cpp
index 7ff0c7227c9c8..a9278c136cff6 100644
--- a/tools/aapt2/ConfigDescription.cpp
+++ b/tools/aapt2/ConfigDescription.cpp
@@ -70,7 +70,7 @@ static bool parseMcc(const char* name, ResTable_config* out) {
 
 static bool parseMnc(const char* name, ResTable_config* out) {
   if (strcmp(name, kWildcardName) == 0) {
-    if (out) out->mcc = 0;
+    if (out) out->mnc = 0;
     return true;
   }
   const char* c = name;
@@ -967,8 +967,6 @@ bool ConfigDescription::ConflictsWith(const ConfigDescription& o) const {
                o.screenLayout & MASK_LAYOUTDIR) ||
          !pred(screenLayout & MASK_SCREENLONG,
                o.screenLayout & MASK_SCREENLONG) ||
-         !pred(screenLayout & MASK_UI_MODE_TYPE,
-               o.screenLayout & MASK_UI_MODE_TYPE) ||
          !pred(uiMode & MASK_UI_MODE_TYPE, o.uiMode & MASK_UI_MODE_TYPE) ||
          !pred(uiMode & MASK_UI_MODE_NIGHT, o.uiMode & MASK_UI_MODE_NIGHT) ||
          !pred(screenLayout2 & MASK_SCREENROUND,
diff --git a/tools/aapt2/ConfigDescription_test.cpp b/tools/aapt2/ConfigDescription_test.cpp
index 14a565624e012..1f351bf7481d9 100644
--- a/tools/aapt2/ConfigDescription_test.cpp
+++ b/tools/aapt2/ConfigDescription_test.cpp
@@ -140,4 +140,16 @@ TEST(ConfigDescriptionTest, ParseVrAttribute) {
   EXPECT_EQ(std::string("vrheadset-v26"), config.toString().string());
 }
 
+TEST(ConfigDescriptionTest, RangeQualifiersDoNotConflict) {
+  using test::ParseConfigOrDie;
+
+  EXPECT_FALSE(ParseConfigOrDie("large").ConflictsWith(ParseConfigOrDie("normal-land")));
+  EXPECT_FALSE(ParseConfigOrDie("long-hdpi").ConflictsWith(ParseConfigOrDie("xhdpi")));
+  EXPECT_FALSE(ParseConfigOrDie("sw600dp").ConflictsWith(ParseConfigOrDie("sw700dp")));
+  EXPECT_FALSE(ParseConfigOrDie("v11").ConflictsWith(ParseConfigOrDie("v21")));
+  EXPECT_FALSE(ParseConfigOrDie("h600dp").ConflictsWith(ParseConfigOrDie("h300dp")));
+  EXPECT_FALSE(ParseConfigOrDie("w400dp").ConflictsWith(ParseConfigOrDie("w300dp")));
+  EXPECT_FALSE(ParseConfigOrDie("600x400").ConflictsWith(ParseConfigOrDie("300x200")));
+}
+
 }  // namespace aapt
diff --git a/tools/aapt2/Debug.cpp b/tools/aapt2/Debug.cpp
index b872ebbeb1598..49ed7780f9501 100644
--- a/tools/aapt2/Debug.cpp
+++ b/tools/aapt2/Debug.cpp
@@ -33,6 +33,8 @@
 
 namespace aapt {
 
+namespace {
+
 class PrintVisitor : public ValueVisitor {
  public:
   using ValueVisitor::Visit;
@@ -88,9 +90,13 @@ class PrintVisitor : public ValueVisitor {
     }
   }
 
-  void Visit(Array* array) override { array->Print(&std::cout); }
+  void Visit(Array* array) override {
+    array->Print(&std::cout);
+  }
 
-  void Visit(Plural* plural) override { plural->Print(&std::cout); }
+  void Visit(Plural* plural) override {
+    plural->Print(&std::cout);
+  }
 
   void Visit(Styleable* styleable) override {
     std::cout << "(styleable)";
@@ -110,11 +116,14 @@ class PrintVisitor : public ValueVisitor {
     }
   }
 
-  void VisitItem(Item* item) override { item->Print(&std::cout); }
+  void VisitItem(Item* item) override {
+    item->Print(&std::cout);
+  }
 };
 
-void Debug::PrintTable(ResourceTable* table,
-                       const DebugPrintTableOptions& options) {
+}  // namespace
+
+void Debug::PrintTable(ResourceTable* table, const DebugPrintTableOptions& options) {
   PrintVisitor visitor;
 
   for (auto& package : table->packages) {
@@ -148,10 +157,9 @@ void Debug::PrintTable(ResourceTable* table,
       }
 
       for (const ResourceEntry* entry : sorted_entries) {
-        ResourceId id(package->id ? package->id.value() : uint8_t(0),
-                      type->id ? type->id.value() : uint8_t(0),
-                      entry->id ? entry->id.value() : uint16_t(0));
-        ResourceName name(package->name, type->type, entry->name);
+        const ResourceId id(package->id.value_or_default(0), type->id.value_or_default(0),
+                            entry->id.value_or_default(0));
+        const ResourceName name(package->name, type->type, entry->name);
 
         std::cout << "    spec resource " << id << " " << name;
         switch (entry->symbol_status.state) {
@@ -180,16 +188,14 @@ void Debug::PrintTable(ResourceTable* table,
   }
 }
 
-static size_t GetNodeIndex(const std::vector<ResourceName>& names,
-                           const ResourceName& name) {
+static size_t GetNodeIndex(const std::vector<ResourceName>& names, const ResourceName& name) {
   auto iter = std::lower_bound(names.begin(), names.end(), name);
   CHECK(iter != names.end());
   CHECK(*iter == name);
   return std::distance(names.begin(), iter);
 }
 
-void Debug::PrintStyleGraph(ResourceTable* table,
-                            const ResourceName& target_style) {
+void Debug::PrintStyleGraph(ResourceTable* table, const ResourceName& target_style) {
   std::map<ResourceName, std::set<ResourceName>> graph;
 
   std::queue<ResourceName> styles_to_visit;
@@ -223,8 +229,7 @@ void Debug::PrintStyleGraph(ResourceTable* table,
 
   std::cout << "digraph styles {\n";
   for (const auto& name : names) {
-    std::cout << "  node_" << GetNodeIndex(names, name) << " [label=\"" << name
-              << "\"];\n";
+    std::cout << "  node_" << GetNodeIndex(names, name) << " [label=\"" << name << "\"];\n";
   }
 
   for (const auto& entry : graph) {
@@ -243,8 +248,7 @@ void Debug::PrintStyleGraph(ResourceTable* table,
 void Debug::DumpHex(const void* data, size_t len) {
   const uint8_t* d = (const uint8_t*)data;
   for (size_t i = 0; i < len; i++) {
-    std::cerr << std::hex << std::setfill('0') << std::setw(2) << (uint32_t)d[i]
-              << " ";
+    std::cerr << std::hex << std::setfill('0') << std::setw(2) << (uint32_t)d[i] << " ";
     if (i % 8 == 7) {
       std::cerr << "\n";
     }
@@ -262,8 +266,15 @@ class XmlPrinter : public xml::Visitor {
   using xml::Visitor::Visit;
 
   void Visit(xml::Element* el) override {
-    std::cerr << prefix_;
-    std::cerr << "E: ";
+    const size_t previous_size = prefix_.size();
+
+    for (const xml::NamespaceDecl& decl : el->namespace_decls) {
+      std::cerr << prefix_ << "N: " << decl.prefix << "=" << decl.uri
+                << " (line=" << decl.line_number << ")\n";
+      prefix_ += "  ";
+    }
+
+    std::cerr << prefix_ << "E: ";
     if (!el->namespace_uri.empty()) {
       std::cerr << el->namespace_uri << ":";
     }
@@ -283,26 +294,13 @@ class XmlPrinter : public xml::Visitor {
       std::cerr << "=" << attr.value << "\n";
     }
 
-    const size_t previous_size = prefix_.size();
     prefix_ += "  ";
     xml::Visitor::Visit(el);
     prefix_.resize(previous_size);
   }
 
-  void Visit(xml::Namespace* ns) override {
-    std::cerr << prefix_;
-    std::cerr << "N: " << ns->namespace_prefix << "=" << ns->namespace_uri
-              << " (line=" << ns->line_number << ")\n";
-
-    const size_t previous_size = prefix_.size();
-    prefix_ += "  ";
-    xml::Visitor::Visit(ns);
-    prefix_.resize(previous_size);
-  }
-
   void Visit(xml::Text* text) override {
-    std::cerr << prefix_;
-    std::cerr << "T: '" << text->text << "'\n";
+    std::cerr << prefix_ << "T: '" << text->text << "'\n";
   }
 
  private:
diff --git a/tools/aapt2/Format.proto b/tools/aapt2/Format.proto
deleted file mode 100644
index 870b735f70a7b..0000000000000
--- a/tools/aapt2/Format.proto
+++ /dev/null
@@ -1,211 +0,0 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-syntax = "proto2";
-
-option optimize_for = LITE_RUNTIME;
-
-package aapt.pb;
-
-message ConfigDescription {
-	optional bytes data = 1;
-	optional string product = 2;
-}
-
-message StringPool {
-	optional bytes data = 1;
-}
-
-message CompiledFile {
-	message Symbol {
-		optional string resource_name = 1;
-		optional uint32 line_no = 2;
-	}
-
-	optional string resource_name = 1;
-	optional ConfigDescription config = 2;
-	optional string source_path = 3;
-	repeated Symbol exported_symbols = 4;
-}
-
-message ResourceTable {
-	optional StringPool string_pool = 1;
-	optional StringPool source_pool = 2;
-	optional StringPool symbol_pool = 3;
-	repeated Package packages = 4;
-}
-
-message Package {
-	optional uint32 package_id = 1;
-	optional string package_name = 2;
-	repeated Type types = 3;
-}
-
-message Type {	
-	optional uint32 id = 1;
-	optional string name = 2;
-	repeated Entry entries = 3;
-}
-
-message SymbolStatus {
-	enum Visibility {
-		Unknown = 0;
-		Private = 1;
-		Public = 2;
-	}
-	optional Visibility visibility = 1;
-	optional Source source = 2;
-	optional string comment = 3;
-	optional bool allow_new = 4;
-}
-
-message Entry {
-	optional uint32 id = 1;
-	optional string name = 2;
-	optional SymbolStatus symbol_status = 3;
-	repeated ConfigValue config_values = 4;
-}
-
-message ConfigValue {
-	optional ConfigDescription config = 1;
-	optional Value value = 2;
-}
-
-message Source {
-	optional uint32 path_idx = 1;
-	optional uint32 line_no = 2;
-	optional uint32 col_no = 3;
-}
-
-message Reference {
-	enum Type {
-		Ref = 0;
-		Attr = 1;
-	}
-	optional Type type = 1;
-	optional uint32 id = 2;
-	optional uint32 symbol_idx = 3;
-	optional bool private = 4;
-}
-
-message Id {
-}
-
-message String {
-	optional uint32 idx = 1;
-}
-
-message RawString {
-	optional uint32 idx = 1;
-}
-
-message FileReference {
-	optional uint32 path_idx = 1;
-}
-
-message Primitive {
-	optional uint32 type = 1;
-	optional uint32 data = 2;
-}
-
-message Attribute {
-	message Symbol {
-		optional Source source = 1;
-		optional string comment = 2;
-		optional Reference name = 3;
-		optional uint32 value = 4;
-	}
-	optional uint32 format_flags = 1;
-	optional int32 min_int = 2;
-	optional int32 max_int = 3;
-	repeated Symbol symbols = 4;
-}
-
-message Style {
-	message Entry {
-		optional Source source = 1;
-		optional string comment = 2;
-		optional Reference key = 3;
-		optional Item item = 4;
-	}
-
-	optional Reference parent = 1;
-	optional Source parent_source = 2;
-	repeated Entry entries = 3;
-}
-
-message Styleable {
-	message Entry {
-		optional Source source = 1;
-		optional string comment = 2;
-		optional Reference attr = 3;
-	}
-	repeated Entry entries = 1;
-}
-
-message Array {
-	message Entry {
-		optional Source source = 1;
-		optional string comment = 2;
-		optional Item item = 3;
-	}
-	repeated Entry entries = 1;
-}
-
-message Plural {
-	enum Arity {
-		Zero = 0;
-		One = 1;
-		Two = 2;
-		Few = 3;
-		Many = 4;
-		Other = 5;
-	}
-		
-	message Entry {
-		optional Source source = 1;
-		optional string comment = 2;
-		optional Arity arity = 3;
-		optional Item item = 4;
-	}
-	repeated Entry entries = 1;
-}
-
-message Item {
-	optional Reference ref = 1;
-	optional String str = 2;
-	optional RawString raw_str = 3;
-	optional FileReference file = 4;
-	optional Id id = 5;
-	optional Primitive prim = 6;
-}
-
-message CompoundValue {
-	optional Attribute attr = 1;
-	optional Style style = 2;
-	optional Styleable styleable = 3;
-	optional Array array = 4;
-	optional Plural plural = 5;
-}
-
-message Value {
-	optional Source source = 1;
-	optional string comment = 2;
-	optional bool weak = 3;
-	
-	optional Item item = 4;
-	optional CompoundValue compound_value = 5;	
-}
diff --git a/tools/aapt2/Main.cpp b/tools/aapt2/Main.cpp
index c5d38abcdf712..36ab30c7fb6e4 100644
--- a/tools/aapt2/Main.cpp
+++ b/tools/aapt2/Main.cpp
@@ -14,12 +14,26 @@
  * limitations under the License.
  */
 
+#ifdef _WIN32
+// clang-format off
+#include <windows.h>
+#include <shellapi.h>
+// clang-format on
+#endif
+
 #include <iostream>
 #include <vector>
 
+#include "android-base/stringprintf.h"
+#include "android-base/utf8.h"
 #include "androidfw/StringPiece.h"
 
 #include "Diagnostics.h"
+#include "util/Files.h"
+#include "util/Util.h"
+
+using ::android::StringPiece;
+using ::android::base::StringPrintf;
 
 namespace aapt {
 
@@ -27,54 +41,136 @@ namespace aapt {
 static const char* sMajorVersion = "2";
 
 // Update minor version whenever a feature or flag is added.
-static const char* sMinorVersion = "18";
+static const char* sMinorVersion = "19";
 
-int PrintVersion() {
-  std::cerr << "Android Asset Packaging Tool (aapt) " << sMajorVersion << "."
-            << sMinorVersion << std::endl;
-  return 0;
+static void PrintVersion() {
+  std::cerr << StringPrintf("Android Asset Packaging Tool (aapt) %s:%s", sMajorVersion,
+                            sMinorVersion)
+            << std::endl;
 }
 
-extern int Compile(const std::vector<android::StringPiece>& args, IDiagnostics* diagnostics);
-extern int Link(const std::vector<android::StringPiece>& args, IDiagnostics* diagnostics);
-extern int Dump(const std::vector<android::StringPiece>& args);
-extern int Diff(const std::vector<android::StringPiece>& args);
-extern int Optimize(const std::vector<android::StringPiece>& args);
+static void PrintUsage() {
+  std::cerr << "\nusage: aapt2 [compile|link|dump|diff|optimize|version] ..." << std::endl;
+}
+
+extern int Compile(const std::vector<StringPiece>& args, IDiagnostics* diagnostics);
+extern int Link(const std::vector<StringPiece>& args, IDiagnostics* diagnostics);
+extern int Dump(const std::vector<StringPiece>& args);
+extern int Diff(const std::vector<StringPiece>& args);
+extern int Optimize(const std::vector<StringPiece>& args);
+
+static int ExecuteCommand(const StringPiece& command, const std::vector<StringPiece>& args,
+                          IDiagnostics* diagnostics) {
+  if (command == "compile" || command == "c") {
+    return Compile(args, diagnostics);
+  } else if (command == "link" || command == "l") {
+    return Link(args, diagnostics);
+  } else if (command == "dump" || command == "d") {
+    return Dump(args);
+  } else if (command == "diff") {
+    return Diff(args);
+  } else if (command == "optimize") {
+    return Optimize(args);
+  } else if (command == "version") {
+    PrintVersion();
+    return 0;
+  }
+  diagnostics->Error(DiagMessage() << "unknown command '" << command << "'");
+  return -1;
+}
+
+static void RunDaemon(IDiagnostics* diagnostics) {
+  std::cout << "Ready" << std::endl;
+
+  // Run in daemon mode. The first line of input is the command. This can be 'quit' which ends
+  // the daemon mode. Each subsequent line is a single parameter to the command. The end of a
+  // invocation is signaled by providing an empty line. At any point, an EOF signal or the
+  // command 'quit' will end the daemon mode.
+  while (true) {
+    std::vector<std::string> raw_args;
+    for (std::string line; std::getline(std::cin, line) && !line.empty();) {
+      raw_args.push_back(line);
+    }
+
+    if (!std::cin) {
+      break;
+    }
+
+    // An empty command does nothing.
+    if (raw_args.empty()) {
+      continue;
+    }
+
+    if (raw_args[0] == "quit") {
+      break;
+    }
+
+    std::vector<StringPiece> args;
+    args.insert(args.end(), ++raw_args.begin(), raw_args.end());
+    int ret = ExecuteCommand(raw_args[0], args, diagnostics);
+    if (ret != 0) {
+      std::cerr << "Error" << std::endl;
+    }
+    std::cerr << "Done" << std::endl;
+  }
+  std::cout << "Exiting daemon" << std::endl;
+}
 
 }  // namespace aapt
 
-int main(int argc, char** argv) {
-  if (argc >= 2) {
-    argv += 1;
-    argc -= 1;
-
-    std::vector<android::StringPiece> args;
-    for (int i = 1; i < argc; i++) {
-      args.push_back(argv[i]);
-    }
-
-    android::StringPiece command(argv[0]);
-    if (command == "compile" || command == "c") {
-      aapt::StdErrDiagnostics diagnostics;
-      return aapt::Compile(args, &diagnostics);
-    } else if (command == "link" || command == "l") {
-      aapt::StdErrDiagnostics diagnostics;
-      return aapt::Link(args, &diagnostics);
-    } else if (command == "dump" || command == "d") {
-      return aapt::Dump(args);
-    } else if (command == "diff") {
-      return aapt::Diff(args);
-    } else if (command == "optimize") {
-      return aapt::Optimize(args);
-    } else if (command == "version") {
-      return aapt::PrintVersion();
-    }
-    std::cerr << "unknown command '" << command << "'\n";
-  } else {
+int MainImpl(int argc, char** argv) {
+  if (argc < 2) {
     std::cerr << "no command specified\n";
+    aapt::PrintUsage();
+    return -1;
   }
 
-  std::cerr << "\nusage: aapt2 [compile|link|dump|diff|optimize|version] ..."
-            << std::endl;
-  return 1;
+  argv += 1;
+  argc -= 1;
+
+  aapt::StdErrDiagnostics diagnostics;
+
+  // Collect the arguments starting after the program name and command name.
+  std::vector<StringPiece> args;
+  for (int i = 1; i < argc; i++) {
+    args.push_back(argv[i]);
+  }
+
+  const StringPiece command(argv[0]);
+  if (command != "daemon" && command != "m") {
+    // Single execution.
+    const int result = aapt::ExecuteCommand(command, args, &diagnostics);
+    if (result < 0) {
+      aapt::PrintUsage();
+    }
+    return result;
+  }
+
+  aapt::RunDaemon(&diagnostics);
+  return 0;
+}
+
+int main(int argc, char** argv) {
+#ifdef _WIN32
+  LPWSTR* wide_argv = CommandLineToArgvW(GetCommandLineW(), &argc);
+  CHECK(wide_argv != nullptr) << "invalid command line parameters passed to process";
+
+  std::vector<std::string> utf8_args;
+  for (int i = 0; i < argc; i++) {
+    std::string utf8_arg;
+    if (!::android::base::WideToUTF8(wide_argv[i], &utf8_arg)) {
+      std::cerr << "error converting input arguments to UTF-8" << std::endl;
+      return 1;
+    }
+    utf8_args.push_back(std::move(utf8_arg));
+  }
+  LocalFree(wide_argv);
+
+  std::unique_ptr<char* []> utf8_argv(new char*[utf8_args.size()]);
+  for (int i = 0; i < argc; i++) {
+    utf8_argv[i] = const_cast<char*>(utf8_args[i].c_str());
+  }
+  argv = utf8_argv.get();
+#endif
+  return MainImpl(argc, argv);
 }
diff --git a/tools/aapt2/Resource.cpp b/tools/aapt2/Resource.cpp
index 35971e7bd99b6..a9f5f298e019f 100644
--- a/tools/aapt2/Resource.cpp
+++ b/tools/aapt2/Resource.cpp
@@ -61,6 +61,8 @@ StringPiece ToString(ResourceType type) {
       return "menu";
     case ResourceType::kMipmap:
       return "mipmap";
+    case ResourceType::kNavigation:
+      return "navigation";
     case ResourceType::kPlurals:
       return "plurals";
     case ResourceType::kRaw:
@@ -98,6 +100,7 @@ static const std::map<StringPiece, ResourceType> sResourceTypeMap{
     {"layout", ResourceType::kLayout},
     {"menu", ResourceType::kMenu},
     {"mipmap", ResourceType::kMipmap},
+    {"navigation", ResourceType::kNavigation},
     {"plurals", ResourceType::kPlurals},
     {"raw", ResourceType::kRaw},
     {"string", ResourceType::kString},
diff --git a/tools/aapt2/Resource.h b/tools/aapt2/Resource.h
index 0a74c1a0f77df..cbcc8fb805aa1 100644
--- a/tools/aapt2/Resource.h
+++ b/tools/aapt2/Resource.h
@@ -59,6 +59,7 @@ enum class ResourceType {
   kLayout,
   kMenu,
   kMipmap,
+  kNavigation,
   kPlurals,
   kRaw,
   kString,
diff --git a/tools/aapt2/ResourceParser.cpp b/tools/aapt2/ResourceParser.cpp
index a5783a532e230..1c3ac2ad4f171 100644
--- a/tools/aapt2/ResourceParser.cpp
+++ b/tools/aapt2/ResourceParser.cpp
@@ -1219,7 +1219,7 @@ bool ResourceParser::ParseArrayImpl(xml::XmlPullParser* parser,
         continue;
       }
       item->SetSource(item_source);
-      array->items.emplace_back(std::move(item));
+      array->elements.emplace_back(std::move(item));
 
     } else if (!ShouldIgnoreElement(element_namespace, element_name)) {
       diag_->Error(DiagMessage(source_.WithLine(parser->line_number()))
diff --git a/tools/aapt2/ResourceParser_test.cpp b/tools/aapt2/ResourceParser_test.cpp
index 1683c64a6a5c0..144ebd22e1054 100644
--- a/tools/aapt2/ResourceParser_test.cpp
+++ b/tools/aapt2/ResourceParser_test.cpp
@@ -22,9 +22,11 @@
 #include "ResourceTable.h"
 #include "ResourceUtils.h"
 #include "ResourceValues.h"
+#include "io/StringInputStream.h"
 #include "test/Test.h"
 #include "xml/XmlPullParser.h"
 
+using ::aapt::io::StringInputStream;
 using ::aapt::test::StrValueEq;
 using ::aapt::test::ValueEq;
 using ::android::ResTable_map;
@@ -43,11 +45,13 @@ constexpr const char* kXmlPreamble = "<?xml version=\"1.0\" encoding=\"utf-8\"?>
 
 TEST(ResourceParserSingleTest, FailToParseWithNoRootResourcesElement) {
   std::unique_ptr<IAaptContext> context = test::ContextBuilder().Build();
-  std::stringstream input(kXmlPreamble);
-  input << R"(<attr name="foo"/>)" << std::endl;
   ResourceTable table;
   ResourceParser parser(context->GetDiagnostics(), &table, Source{"test"}, {});
-  xml::XmlPullParser xml_parser(input);
+
+  std::string input = kXmlPreamble;
+  input += R"(<attr name="foo"/>)";
+  StringInputStream in(input);
+  xml::XmlPullParser xml_parser(&in);
   ASSERT_FALSE(parser.Parse(&xml_parser));
 }
 
@@ -62,12 +66,16 @@ class ResourceParserTest : public ::testing::Test {
   }
 
   ::testing::AssertionResult TestParse(const StringPiece& str, const ConfigDescription& config) {
-    std::stringstream input(kXmlPreamble);
-    input << "<resources>\n" << str << "\n</resources>" << std::endl;
     ResourceParserOptions parserOptions;
     ResourceParser parser(context_->GetDiagnostics(), &table_, Source{"test"}, config,
                           parserOptions);
-    xml::XmlPullParser xmlParser(input);
+
+    std::string input = kXmlPreamble;
+    input += "<resources>\n";
+    input.append(str.data(), str.size());
+    input += "\n</resources>";
+    StringInputStream in(input);
+    xml::XmlPullParser xmlParser(&in);
     if (parser.Parse(&xmlParser)) {
       return ::testing::AssertionSuccess();
     }
@@ -532,11 +540,11 @@ TEST_F(ResourceParserTest, ParseArray) {
 
   Array* array = test::GetValue<Array>(&table_, "array/foo");
   ASSERT_THAT(array, NotNull());
-  ASSERT_THAT(array->items, SizeIs(3));
+  ASSERT_THAT(array->elements, SizeIs(3));
 
-  EXPECT_THAT(ValueCast<Reference>(array->items[0].get()), NotNull());
-  EXPECT_THAT(ValueCast<String>(array->items[1].get()), NotNull());
-  EXPECT_THAT(ValueCast<BinaryPrimitive>(array->items[2].get()), NotNull());
+  EXPECT_THAT(ValueCast<Reference>(array->elements[0].get()), NotNull());
+  EXPECT_THAT(ValueCast<String>(array->elements[1].get()), NotNull());
+  EXPECT_THAT(ValueCast<BinaryPrimitive>(array->elements[2].get()), NotNull());
 }
 
 TEST_F(ResourceParserTest, ParseStringArray) {
@@ -557,9 +565,9 @@ TEST_F(ResourceParserTest, ParseArrayWithFormat) {
 
   Array* array = test::GetValue<Array>(&table_, "array/foo");
   ASSERT_THAT(array, NotNull());
-  ASSERT_THAT(array->items, SizeIs(1));
+  ASSERT_THAT(array->elements, SizeIs(1));
 
-  String* str = ValueCast<String>(array->items[0].get());
+  String* str = ValueCast<String>(array->elements[0].get());
   ASSERT_THAT(str, NotNull());
   EXPECT_THAT(*str, StrValueEq("100"));
 }
diff --git a/tools/aapt2/ResourceValues.cpp b/tools/aapt2/ResourceValues.cpp
index eb59175edf3b1..1cba194628399 100644
--- a/tools/aapt2/ResourceValues.cpp
+++ b/tools/aapt2/ResourceValues.cpp
@@ -805,13 +805,12 @@ bool Array::Equals(const Value* value) const {
     return false;
   }
 
-  if (items.size() != other->items.size()) {
+  if (elements.size() != other->elements.size()) {
     return false;
   }
 
-  return std::equal(items.begin(), items.end(), other->items.begin(),
-                    [](const std::unique_ptr<Item>& a,
-                       const std::unique_ptr<Item>& b) -> bool {
+  return std::equal(elements.begin(), elements.end(), other->elements.begin(),
+                    [](const std::unique_ptr<Item>& a, const std::unique_ptr<Item>& b) -> bool {
                       return a->Equals(b.get());
                     });
 }
@@ -820,14 +819,14 @@ Array* Array::Clone(StringPool* new_pool) const {
   Array* array = new Array();
   array->comment_ = comment_;
   array->source_ = source_;
-  for (auto& item : items) {
-    array->items.emplace_back(std::unique_ptr<Item>(item->Clone(new_pool)));
+  for (auto& item : elements) {
+    array->elements.emplace_back(std::unique_ptr<Item>(item->Clone(new_pool)));
   }
   return array;
 }
 
 void Array::Print(std::ostream* out) const {
-  *out << "(array) [" << util::Joiner(items, ", ") << "]";
+  *out << "(array) [" << util::Joiner(elements, ", ") << "]";
 }
 
 bool Plural::Equals(const Value* value) const {
diff --git a/tools/aapt2/ResourceValues.h b/tools/aapt2/ResourceValues.h
index 7e7547fc1b94b..275864bbcd3e4 100644
--- a/tools/aapt2/ResourceValues.h
+++ b/tools/aapt2/ResourceValues.h
@@ -292,7 +292,7 @@ struct Style : public BaseValue<Style> {
 };
 
 struct Array : public BaseValue<Array> {
-  std::vector<std::unique_ptr<Item>> items;
+  std::vector<std::unique_ptr<Item>> elements;
 
   bool Equals(const Value* value) const override;
   Array* Clone(StringPool* new_pool) const override;
diff --git a/tools/aapt2/ResourceValues_test.cpp b/tools/aapt2/ResourceValues_test.cpp
index 06c3404561de8..10f9b55ede08e 100644
--- a/tools/aapt2/ResourceValues_test.cpp
+++ b/tools/aapt2/ResourceValues_test.cpp
@@ -54,19 +54,19 @@ TEST(ResourceValuesTest, ArrayEquals) {
   StringPool pool;
 
   Array a;
-  a.items.push_back(util::make_unique<String>(pool.MakeRef("one")));
-  a.items.push_back(util::make_unique<String>(pool.MakeRef("two")));
+  a.elements.push_back(util::make_unique<String>(pool.MakeRef("one")));
+  a.elements.push_back(util::make_unique<String>(pool.MakeRef("two")));
 
   Array b;
-  b.items.push_back(util::make_unique<String>(pool.MakeRef("une")));
-  b.items.push_back(util::make_unique<String>(pool.MakeRef("deux")));
+  b.elements.push_back(util::make_unique<String>(pool.MakeRef("une")));
+  b.elements.push_back(util::make_unique<String>(pool.MakeRef("deux")));
 
   Array c;
-  c.items.push_back(util::make_unique<String>(pool.MakeRef("uno")));
+  c.elements.push_back(util::make_unique<String>(pool.MakeRef("uno")));
 
   Array d;
-  d.items.push_back(util::make_unique<String>(pool.MakeRef("one")));
-  d.items.push_back(util::make_unique<String>(pool.MakeRef("two")));
+  d.elements.push_back(util::make_unique<String>(pool.MakeRef("one")));
+  d.elements.push_back(util::make_unique<String>(pool.MakeRef("two")));
 
   EXPECT_FALSE(a.Equals(&b));
   EXPECT_FALSE(a.Equals(&c));
@@ -78,8 +78,8 @@ TEST(ResourceValuesTest, ArrayClone) {
   StringPool pool;
 
   Array a;
-  a.items.push_back(util::make_unique<String>(pool.MakeRef("one")));
-  a.items.push_back(util::make_unique<String>(pool.MakeRef("two")));
+  a.elements.push_back(util::make_unique<String>(pool.MakeRef("one")));
+  a.elements.push_back(util::make_unique<String>(pool.MakeRef("two")));
 
   std::unique_ptr<Array> b(a.Clone(&pool));
   EXPECT_TRUE(a.Equals(b.get()));
diff --git a/tools/aapt2/Resource_test.cpp b/tools/aapt2/Resource_test.cpp
index ad4e3ce02b32b..c557f3c776544 100644
--- a/tools/aapt2/Resource_test.cpp
+++ b/tools/aapt2/Resource_test.cpp
@@ -93,6 +93,10 @@ TEST(ResourceTypeTest, ParseResourceTypes) {
   ASSERT_NE(type, nullptr);
   EXPECT_EQ(*type, ResourceType::kMipmap);
 
+  type = ParseResourceType("navigation");
+  ASSERT_NE(type, nullptr);
+  EXPECT_EQ(*type, ResourceType::kNavigation);
+
   type = ParseResourceType("plurals");
   ASSERT_NE(type, nullptr);
   EXPECT_EQ(*type, ResourceType::kPlurals);
diff --git a/tools/aapt2/Resources.proto b/tools/aapt2/Resources.proto
new file mode 100644
index 0000000000000..71f33b0853ad4
--- /dev/null
+++ b/tools/aapt2/Resources.proto
@@ -0,0 +1,471 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Keep proto2 syntax because we require the distinction between fields that
+// are set and unset.
+syntax = "proto2";
+
+option java_package = "com.android.aapt";
+option optimize_for = LITE_RUNTIME;
+
+package aapt.pb;
+
+// A configuration description that wraps the binary form of the C++ class
+// aapt::ConfigDescription, with an added product definition.
+// TODO(adamlesinski): Flesh this out to be represented in proto.
+message ConfigDescription {
+  optional bytes data = 1;
+  optional string product = 2;
+}
+
+// A string pool that wraps the binary form of the C++ class android::ResStringPool.
+message StringPool {
+  optional bytes data = 1;
+}
+
+// The position of a declared entity within a file.
+message SourcePosition {
+  optional uint32 line_number = 1;
+  optional uint32 column_number = 2;
+}
+
+// Developer friendly source file information for an entity in the resource table.
+message Source {
+  // The index of the string path within the source string pool of a ResourceTable.
+  optional uint32 path_idx = 1;
+  optional SourcePosition position = 2;
+}
+
+// Top level message representing a resource table.
+message ResourceTable {
+  // The string pool containing source paths referenced throughout the resource table. This does
+  // not end up in the final binary ARSC file.
+  optional StringPool source_pool = 1;
+
+  // Resource definitions corresponding to an Android package.
+  repeated Package package = 2;
+}
+
+// Defines resources for an Android package.
+message Package {
+  // The package ID of this package, in the range [0x00, 0xff].
+  // The ID 0x00 is reserved for shared libraries, or when the ID is assigned at run-time.
+  // The ID 0x01 is reserved for the 'android' package (framework).
+  // The ID range [0x02, 0x7f) is reserved for auto-assignment to shared libraries at run-time.
+  // The ID 0x7f is reserved for the application package.
+  // IDs > 0x7f are reserved for the application as well and are treated as feature splits.
+  optional uint32 package_id = 1;
+
+  // The Java compatible Android package name of the app.
+  optional string package_name = 2;
+
+  // The series of types defined by the package.
+  repeated Type type = 3;
+}
+
+// A set of resources grouped under a common type. Such types include string, layout, xml, dimen,
+// attr, etc. This maps to the second part of a resource identifier in Java (R.type.entry).
+message Type {
+  // The ID of the type. This may be 0, which indicates no ID is set.
+  optional uint32 id = 1;
+
+  // The name of the type. This corresponds to the 'type' part of a full resource name of the form
+  // package:type/entry. The set of legal type names is listed in Resource.cpp.
+  optional string name = 2;
+
+  // The entries defined for this type.
+  repeated Entry entry = 3;
+}
+
+// The status of a symbol/entry. This contains information like visibility (public/private),
+// comments, and whether the entry can be overridden.
+message SymbolStatus {
+  // The visibility of the resource outside of its package.
+  enum Visibility {
+    // No visibility was explicitly specified. This is typically treated as private.
+    // The distinction is important when two separate R.java files are generated: a public and
+    // private one. An unknown visibility, in this case, would cause the resource to be omitted
+    // from either R.java.
+    UNKNOWN = 0;
+
+    // A resource was explicitly marked as private. This means the resource can not be accessed
+    // outside of its package unless the @*package:type/entry notation is used (the asterisk being
+    // the private accessor). If two R.java files are generated (private + public), the resource
+    // will only be emitted to the private R.java file.
+    PRIVATE = 1;
+
+    // A resource was explicitly marked as public. This means the resource can be accessed
+    // from any package, and is emitted into all R.java files, public and private.
+    PUBLIC = 2;
+  }
+
+  optional Visibility visibility = 1;
+
+  // The path at which this entry's visibility was defined (eg. public.xml).
+  optional Source source = 2;
+
+  // The comment associated with the <public> tag.
+  optional string comment = 3;
+
+  // Whether the symbol can be merged into another resource table without there being an existing
+  // definition to override. Used for overlays and set to true when <add-resource> is specified.
+  optional bool allow_new = 4;
+}
+
+// An entry declaration. An entry has a full resource ID that is the combination of package ID,
+// type ID, and its own entry ID. An entry on its own has no value, but values are defined for
+// various configurations/variants.
+message Entry {
+  // The ID of this entry. Together with the package ID and type ID, this forms a full resource ID
+  // of the form 0xPPTTEEEE, where PP is the package ID, TT is the type ID, and EEEE is the entry
+  // ID.
+  optional uint32 id = 1;
+
+  // The name of this entry. This corresponds to the 'entry' part of a full resource name of the
+  // form package:type/entry.
+  optional string name = 2;
+
+  // The symbol status of this entry, which includes visibility information.
+  optional SymbolStatus symbol_status = 3;
+
+  // The set of values defined for this entry, each corresponding to a different
+  // configuration/variant.
+  repeated ConfigValue config_value = 4;
+}
+
+// A Configuration/Value pair.
+message ConfigValue {
+  optional ConfigDescription config = 1;
+  optional Value value = 2;
+}
+
+// The generic meta-data for every value in a resource table.
+message Value {
+  // Where the value was defined.
+  optional Source source = 1;
+
+  // Any comment associated with the value.
+  optional string comment = 2;
+
+  // Whether the value can be overridden.
+  optional bool weak = 3;
+
+  // If the value is an Item, this is set.
+  optional Item item = 4;
+
+  // If the value is a CompoundValue, this is set.
+  optional CompoundValue compound_value = 5;
+}
+
+// An Item is an abstract type. It represents a value that can appear inline in many places, such
+// as XML attribute values or on the right hand side of style attribute definitions. The concrete
+// type is one of the types below. Only one can be set.
+message Item {
+  optional Reference ref = 1;
+  optional String str = 2;
+  optional RawString raw_str = 3;
+  optional StyledString styled_str = 4;
+  optional FileReference file = 5;
+  optional Id id = 6;
+  optional Primitive prim = 7;
+}
+
+// A CompoundValue is an abstract type. It represents a value that is a made of other values.
+// These can only usually appear as top-level resources. The concrete type is one of the types
+// below. Only one can be set.
+message CompoundValue {
+  optional Attribute attr = 1;
+  optional Style style = 2;
+  optional Styleable styleable = 3;
+  optional Array array = 4;
+  optional Plural plural = 5;
+}
+
+// A value that is a reference to another resource. This reference can be by name or resource ID.
+message Reference {
+  enum Type {
+    // A plain reference (@package:type/entry).
+    REFERENCE = 0;
+
+    // A reference to a theme attribute (?package:type/entry).
+    ATTRIBUTE = 1;
+  }
+
+  optional Type type = 1;
+
+  // The resource ID (0xPPTTEEEE) of the resource being referred.
+  optional uint32 id = 2;
+
+  // The optional resource name.
+  optional string name = 3;
+
+  // Whether this reference is referencing a private resource (@*package:type/entry).
+  optional bool private = 4;
+}
+
+// A value that represents an ID. This is just a placeholder, as ID values are used to occupy a
+// resource ID (0xPPTTEEEE) as a unique identifier. Their value is unimportant.
+message Id {
+}
+
+// A value that is a string.
+message String {
+  optional string value = 1;
+}
+
+// A value that is a raw string, which is unescaped/uninterpreted. This is typically used to
+// represent the value of a style attribute before the attribute is compiled and the set of
+// allowed values is known.
+message RawString {
+  optional string value = 1;
+}
+
+// A string with styling information, like html tags that specify boldness, italics, etc.
+message StyledString {
+  // The raw text of the string.
+  optional string value = 1;
+
+  // A Span marks a region of the string text that is styled.
+  message Span {
+    // The name of the tag, and its attributes, encoded as follows:
+    // tag_name;attr1=value1;attr2=value2;[...]
+    optional string tag = 1;
+
+    // The first character position this span applies to, in UTF-16 offset.
+    optional uint32 first_char = 2;
+
+    // The last character position this span applies to, in UTF-16 offset.
+    optional uint32 last_char = 3;
+  }
+
+  repeated Span span = 2;
+}
+
+// A value that is a reference to an external entity, like an XML file or a PNG.
+message FileReference {
+  // Path to a file within the APK (typically res/type-config/entry.ext).
+  optional string path = 1;
+}
+
+// A value that represents a primitive data type (float, int, boolean, etc.).
+// Corresponds to the fields (type/data) of the C struct android::Res_value.
+message Primitive {
+  optional uint32 type = 1;
+  optional uint32 data = 2;
+}
+
+// A value that represents an XML attribute and what values it accepts.
+message Attribute {
+  // A Symbol used to represent an enum or a flag.
+  message Symbol {
+    // Where the enum/flag item was defined.
+    optional Source source = 1;
+
+    // Any comments associated with the enum or flag.
+    optional string comment = 2;
+
+    // The name of the enum/flag as a reference. Enums/flag items are generated as ID resource
+    // values.
+    optional Reference name = 3;
+
+    // The value of the enum/flag.
+    optional uint32 value = 4;
+  }
+
+  // Bitmask of formats allowed for an attribute.
+  enum FormatFlags {
+    ANY = 0x0000ffff;    // Allows any type except ENUM and FLAGS.
+    REFERENCE = 0x01;    // Allows Reference values.
+    STRING = 0x02;       // Allows String/StyledString values.
+    INTEGER = 0x04;      // Allows any integer BinaryPrimitive values.
+    BOOLEAN = 0x08;      // Allows any boolean BinaryPrimitive values.
+    COLOR = 0x010;       // Allows any color BinaryPrimitive values.
+    FLOAT = 0x020;       // Allows any float BinaryPrimitive values.
+    DIMENSION = 0x040;   // Allows any dimension BinaryPrimitive values.
+    FRACTION = 0x080;    // Allows any fraction BinaryPrimitive values.
+    ENUM = 0x00010000;   // Allows enums that are defined in the Attribute's symbols.
+                         // ENUM and FLAGS cannot BOTH be set.
+    FLAGS = 0x00020000;  // Allows flags that are defined in the Attribute's symbols.
+                         // ENUM and FLAGS cannot BOTH be set.
+  }
+
+  // A bitmask of types that this XML attribute accepts. Corresponds to the flags in the
+  // enum FormatFlags.
+  optional uint32 format_flags = 1;
+
+  // The smallest integer allowed for this XML attribute. Only makes sense if the format includes
+  // FormatFlags::INTEGER.
+  optional int32 min_int = 2;
+
+  // The largest integer allowed for this XML attribute. Only makes sense if the format includes
+  // FormatFlags::INTEGER.
+  optional int32 max_int = 3;
+
+  // The set of enums/flags defined in this attribute. Only makes sense if the format includes
+  // either FormatFlags::ENUM or FormatFlags::FLAGS. Having both is an error.
+  repeated Symbol symbol = 4;
+}
+
+// A value that represents a style.
+message Style {
+  // An XML attribute/value pair defined in the style.
+  message Entry {
+    // Where the entry was defined.
+    optional Source source = 1;
+
+    // Any comments associated with the entry.
+    optional string comment = 2;
+
+    // A reference to the XML attribute.
+    optional Reference key = 3;
+
+    // The Item defined for this XML attribute.
+    optional Item item = 4;
+  }
+
+  // The optinal style from which this style inherits attributes.
+  optional Reference parent = 1;
+
+  // The source file information of the parent inheritance declaration.
+  optional Source parent_source = 2;
+
+  // The set of XML attribute/value pairs for this style.
+  repeated Entry entry = 3;
+}
+
+// A value that represents a <declare-styleable> XML resource. These are not real resources and
+// only end up as Java fields in the generated R.java. They do not end up in the binary ARSC file.
+message Styleable {
+  // An attribute defined for this styleable.
+  message Entry {
+    // Where the attribute was defined within the <declare-styleable> block.
+    optional Source source = 1;
+
+    // Any comments associated with the declaration.
+    optional string comment = 2;
+
+    // The reference to the attribute.
+    optional Reference attr = 3;
+  }
+
+  // The set of attribute declarations.
+  repeated Entry entry = 1;
+}
+
+// A value that represents an array of resource values.
+message Array {
+  // A single element of the array.
+  message Element {
+    // Where the element was defined.
+    optional Source source = 1;
+
+    // Any comments associated with the element.
+    optional string comment = 2;
+
+    // The value assigned to this element.
+    optional Item item = 3;
+  }
+
+  // The list of array elements.
+  repeated Element element = 1;
+}
+
+// A value that represents a string and its many variations based on plurality.
+message Plural {
+  // The arity of the plural.
+  enum Arity {
+    ZERO = 0;
+    ONE = 1;
+    TWO = 2;
+    FEW = 3;
+    MANY = 4;
+    OTHER = 5;
+  }
+
+  // The plural value for a given arity.
+  message Entry {
+    // Where the plural was defined.
+    optional Source source = 1;
+
+    // Any comments associated with the plural.
+    optional string comment = 2;
+
+    // The arity of the plural.
+    optional Arity arity = 3;
+
+    // The value assigned to this plural.
+    optional Item item = 4;
+  }
+
+  // The set of arity/plural mappings.
+  repeated Entry entry = 1;
+}
+
+// Defines an abstract XmlNode that must be either an XmlElement, or
+// a text node represented by a string.
+message XmlNode {
+  // If set, this node is an element/tag.
+  optional XmlElement element = 1;
+
+  // If set, this node is a chunk of text.
+  optional string text = 2;
+
+  // Source line and column info.
+  optional SourcePosition source = 3;
+}
+
+// An <element> in an XML document.
+message XmlElement {
+  // Namespaces defined on this element.
+  repeated XmlNamespace namespace_declaration = 1;
+
+  // The namespace URI of this element.
+  optional string namespace_uri = 2;
+
+  // The name of this element.
+  optional string name = 3;
+
+  // The attributes of this element.
+  repeated XmlAttribute attribute = 4;
+
+  // The children of this element.
+  repeated XmlNode child = 5;
+}
+
+// A namespace declaration on an XmlElement (xmlns:android="http://...").
+message XmlNamespace {
+  optional string prefix = 1;
+  optional string uri = 2;
+
+  // Source line and column info.
+  optional SourcePosition source = 3;
+}
+
+// An attribute defined on an XmlElement (android:text="...").
+message XmlAttribute {
+  optional string namespace_uri = 1;
+  optional string name = 2;
+  optional string value = 3;
+
+  // Source line and column info.
+  optional SourcePosition source = 4;
+
+  // The resource ID (0xPPTTEEEE) of the attribute.
+  optional uint32 resource_id = 5;
+
+  // The interpreted/compiled version of the `value` string.
+  optional Item compiled_item = 6;
+}
diff --git a/tools/aapt2/ResourcesInternal.proto b/tools/aapt2/ResourcesInternal.proto
new file mode 100644
index 0000000000000..31179174b8437
--- /dev/null
+++ b/tools/aapt2/ResourcesInternal.proto
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+syntax = "proto2";
+
+option java_package = "android.aapt.pb.internal";
+option optimize_for = LITE_RUNTIME;
+
+import "frameworks/base/tools/aapt2/Resources.proto";
+
+package aapt.pb.internal;
+
+// The top level message representing an external resource file (layout XML, PNG, etc).
+// This is used to represent a compiled file before it is linked. Only useful to aapt2.
+message CompiledFile {
+  message Symbol {
+    // The name of the symbol (in the form package:type/name).
+    optional string resource_name = 1;
+
+    // The position in the file at which this symbol is defined. For debug use.
+    optional aapt.pb.SourcePosition source = 2;
+  }
+
+  // The name of the resource (in the form package:type/name).
+  optional string resource_name = 1;
+
+  // The configuration for which the resource is defined.
+  optional aapt.pb.ConfigDescription config = 2;
+
+  // The filesystem path to where the source file originated.
+  // Mainly used to display helpful error messages.
+  optional string source_path = 3;
+
+  // Any symbols this file auto-generates/exports (eg. @+id/foo in an XML file).
+  repeated Symbol exported_symbol = 4;
+
+  // If this is a compiled XML file, this is the root node.
+  optional aapt.pb.XmlNode xml_root = 5;
+}
diff --git a/tools/aapt2/ValueVisitor.h b/tools/aapt2/ValueVisitor.h
index 2763d49f15c41..eb4fa494e53f3 100644
--- a/tools/aapt2/ValueVisitor.h
+++ b/tools/aapt2/ValueVisitor.h
@@ -80,7 +80,7 @@ struct ValueVisitor : public RawValueVisitor {
   }
 
   void VisitSubValues(Array* array) {
-    for (std::unique_ptr<Item>& item : array->items) {
+    for (std::unique_ptr<Item>& item : array->elements) {
       item->Accept(this);
     }
   }
diff --git a/tools/aapt2/cmd/Compile.cpp b/tools/aapt2/cmd/Compile.cpp
index b64cd8c432d41..7f5bbf0427660 100644
--- a/tools/aapt2/cmd/Compile.cpp
+++ b/tools/aapt2/cmd/Compile.cpp
@@ -16,11 +16,11 @@
 
 #include <dirent.h>
 
-#include <fstream>
 #include <string>
 
 #include "android-base/errors.h"
 #include "android-base/file.h"
+#include "android-base/utf8.h"
 #include "androidfw/StringPiece.h"
 #include "google/protobuf/io/coded_stream.h"
 #include "google/protobuf/io/zero_copy_stream_impl_lite.h"
@@ -38,6 +38,7 @@
 #include "flatten/Archive.h"
 #include "flatten/XmlFlattener.h"
 #include "io/BigBufferOutputStream.h"
+#include "io/FileInputStream.h"
 #include "io/Util.h"
 #include "proto/ProtoSerialize.h"
 #include "util/Files.h"
@@ -46,8 +47,9 @@
 #include "xml/XmlDom.h"
 #include "xml/XmlPullParser.h"
 
-using android::StringPiece;
-using google::protobuf::io::CopyingOutputStreamAdaptor;
+using ::aapt::io::FileInputStream;
+using ::android::StringPiece;
+using ::google::protobuf::io::CopyingOutputStreamAdaptor;
 
 namespace aapt {
 
@@ -57,19 +59,14 @@ struct ResourcePathData {
   std::string name;
   std::string extension;
 
-  // Original config str. We keep this because when we parse the config, we may
-  // add on
-  // version qualifiers. We want to preserve the original input so the output is
-  // easily
+  // Original config str. We keep this because when we parse the config, we may add on
+  // version qualifiers. We want to preserve the original input so the output is easily
   // computed before hand.
   std::string config_str;
   ConfigDescription config;
 };
 
-/**
- * Resource file paths are expected to look like:
- * [--/res/]type[-config]/name
- */
+// Resource file paths are expected to look like: [--/res/]type[-config]/name
 static Maybe<ResourcePathData> ExtractResourcePathData(const std::string& path,
                                                        std::string* out_error) {
   std::vector<std::string> parts = util::Split(path, file::sDirSep);
@@ -137,9 +134,7 @@ static bool IsHidden(const StringPiece& filename) {
   return util::StartsWith(filename, ".");
 }
 
-/**
- * Walks the res directory structure, looking for resource files.
- */
+// Walks the res directory structure, looking for resource files.
 static bool LoadInputFilesFromDir(IAaptContext* context, const CompileOptions& options,
                                   std::vector<ResourcePathData>* out_path_data) {
   const std::string& root_dir = options.res_dir.value();
@@ -195,22 +190,20 @@ static bool CompileTable(IAaptContext* context, const CompileOptions& options,
                          const std::string& output_path) {
   ResourceTable table;
   {
-    std::ifstream fin(path_data.source.path, std::ifstream::binary);
-    if (!fin) {
+    FileInputStream fin(path_data.source.path);
+    if (fin.HadError()) {
       context->GetDiagnostics()->Error(DiagMessage(path_data.source)
-                                       << "failed to open file: "
-                                       << android::base::SystemErrorCodeToString(errno));
+                                       << "failed to open file: " << fin.GetError());
       return false;
     }
 
     // Parse the values file from XML.
-    xml::XmlPullParser xml_parser(fin);
+    xml::XmlPullParser xml_parser(&fin);
 
     ResourceParserOptions parser_options;
     parser_options.error_on_positional_arguments = !options.legacy_mode;
 
-    // If the filename includes donottranslate, then the default translatable is
-    // false.
+    // If the filename includes donottranslate, then the default translatable is false.
     parser_options.translatable = path_data.name.find("donottranslate") == std::string::npos;
 
     ResourceParser res_parser(context->GetDiagnostics(), &table, path_data.source, path_data.config,
@@ -218,8 +211,6 @@ static bool CompileTable(IAaptContext* context, const CompileOptions& options,
     if (!res_parser.Parse(&xml_parser)) {
       return false;
     }
-
-    fin.close();
   }
 
   if (options.pseudolocalize) {
@@ -239,8 +230,7 @@ static bool CompileTable(IAaptContext* context, const CompileOptions& options,
   // Assign an ID to any package that has resources.
   for (auto& pkg : table.packages) {
     if (!pkg->id) {
-      // If no package ID was set while parsing (public identifiers), auto
-      // assign an ID.
+      // If no package ID was set while parsing (public identifiers), auto assign an ID.
       pkg->id = context->GetPackageId();
     }
   }
@@ -292,7 +282,7 @@ static bool WriteHeaderAndBufferToWriter(const StringPiece& output_path, const R
     // Number of CompiledFiles.
     output_stream.WriteLittleEndian32(1);
 
-    std::unique_ptr<pb::CompiledFile> compiled_file = SerializeCompiledFileToPb(file);
+    std::unique_ptr<pb::internal::CompiledFile> compiled_file = SerializeCompiledFileToPb(file);
     output_stream.WriteCompiledFile(compiled_file.get());
     output_stream.WriteData(&buffer);
 
@@ -329,7 +319,7 @@ static bool WriteHeaderAndMmapToWriter(const StringPiece& output_path, const Res
     // Number of CompiledFiles.
     output_stream.WriteLittleEndian32(1);
 
-    std::unique_ptr<pb::CompiledFile> compiled_file = SerializeCompiledFileToPb(file);
+    std::unique_ptr<pb::internal::CompiledFile> compiled_file = SerializeCompiledFileToPb(file);
     output_stream.WriteCompiledFile(compiled_file.get());
     output_stream.WriteData(map.getDataPtr(), map.getDataLength());
 
@@ -356,7 +346,8 @@ static bool FlattenXmlToOutStream(IAaptContext* context, const StringPiece& outp
     return false;
   }
 
-  std::unique_ptr<pb::CompiledFile> pb_compiled_file = SerializeCompiledFileToPb(xmlres->file);
+  std::unique_ptr<pb::internal::CompiledFile> pb_compiled_file =
+      SerializeCompiledFileToPb(xmlres->file);
   out->WriteCompiledFile(pb_compiled_file.get());
   out->WriteData(&buffer);
 
@@ -367,7 +358,7 @@ static bool FlattenXmlToOutStream(IAaptContext* context, const StringPiece& outp
   return true;
 }
 
-static bool IsValidFile(IAaptContext* context, const StringPiece& input_path) {
+static bool IsValidFile(IAaptContext* context, const std::string& input_path) {
   const file::FileType file_type = file::GetFileType(input_path);
   if (file_type != file::FileType::kRegular && file_type != file::FileType::kSymlink) {
     if (file_type == file::FileType::kDirectory) {
@@ -393,17 +384,14 @@ static bool CompileXml(IAaptContext* context, const CompileOptions& options,
 
   std::unique_ptr<xml::XmlResource> xmlres;
   {
-    std::ifstream fin(path_data.source.path, std::ifstream::binary);
-    if (!fin) {
+    FileInputStream fin(path_data.source.path);
+    if (fin.HadError()) {
       context->GetDiagnostics()->Error(DiagMessage(path_data.source)
-                                       << "failed to open file: "
-                                       << android::base::SystemErrorCodeToString(errno));
+                                       << "failed to open file: " << fin.GetError());
       return false;
     }
 
     xmlres = xml::Inflate(&fin, context->GetDiagnostics(), path_data.source);
-
-    fin.close();
   }
 
   if (!xmlres) {
@@ -432,12 +420,9 @@ static bool CompileXml(IAaptContext* context, const CompileOptions& options,
     return false;
   }
 
-  // Make sure CopyingOutputStreamAdaptor is deleted before we call
-  // writer->FinishEntry().
+  // Make sure CopyingOutputStreamAdaptor is deleted before we call writer->FinishEntry().
   {
-    // Wrap our IArchiveWriter with an adaptor that implements the
-    // ZeroCopyOutputStream
-    // interface.
+    // Wrap our IArchiveWriter with an adaptor that implements the ZeroCopyOutputStream interface.
     CopyingOutputStreamAdaptor copying_adaptor(writer);
     CompiledFileOutputStream output_stream(&copying_adaptor);
 
diff --git a/tools/aapt2/cmd/Dump.cpp b/tools/aapt2/cmd/Dump.cpp
index aa9472361def6..0965910ca8539 100644
--- a/tools/aapt2/cmd/Dump.cpp
+++ b/tools/aapt2/cmd/Dump.cpp
@@ -27,11 +27,11 @@
 #include "unflatten/BinaryResourceParser.h"
 #include "util/Files.h"
 
-using android::StringPiece;
+using ::android::StringPiece;
 
 namespace aapt {
 
-bool DumpCompiledFile(const pb::CompiledFile& pb_file, const void* data, size_t len,
+bool DumpCompiledFile(const pb::internal::CompiledFile& pb_file, const void* data, size_t len,
                       const Source& source, IAaptContext* context) {
   std::unique_ptr<ResourceFile> file =
       DeserializeCompiledFileFromPb(pb_file, source, context->GetDiagnostics());
@@ -118,7 +118,7 @@ bool TryDumpFile(IAaptContext* context, const std::string& file_path) {
       }
 
       for (uint32_t i = 0; i < num_files; i++) {
-        pb::CompiledFile compiled_file;
+        pb::internal::CompiledFile compiled_file;
         if (!input.ReadCompiledFile(&compiled_file)) {
           context->GetDiagnostics()->Warn(DiagMessage() << "failed to read compiled file");
           return false;
diff --git a/tools/aapt2/cmd/Link.cpp b/tools/aapt2/cmd/Link.cpp
index 5ad0cdd995ed9..d9e7ac6c1e087 100644
--- a/tools/aapt2/cmd/Link.cpp
+++ b/tools/aapt2/cmd/Link.cpp
@@ -40,6 +40,7 @@
 #include "flatten/TableFlattener.h"
 #include "flatten/XmlFlattener.h"
 #include "io/BigBufferInputStream.h"
+#include "io/FileInputStream.h"
 #include "io/FileSystem.h"
 #include "io/Util.h"
 #include "io/ZipArchive.h"
@@ -61,8 +62,9 @@
 #include "util/Files.h"
 #include "xml/XmlDom.h"
 
-using android::StringPiece;
-using android::base::StringPrintf;
+using ::aapt::io::FileInputStream;
+using ::android::StringPiece;
+using ::android::base::StringPrintf;
 
 namespace aapt {
 
@@ -284,13 +286,11 @@ static std::unique_ptr<ResourceTable> LoadTableFromPb(const Source& source, cons
   return table;
 }
 
-/**
- * Inflates an XML file from the source path.
- */
+// Inflates an XML file from the source path.
 static std::unique_ptr<xml::XmlResource> LoadXml(const std::string& path, IDiagnostics* diag) {
-  std::ifstream fin(path, std::ifstream::binary);
-  if (!fin) {
-    diag->Error(DiagMessage(path) << strerror(errno));
+  FileInputStream fin(path);
+  if (fin.HadError()) {
+    diag->Error(DiagMessage(path) << "failed to load XML file: " << fin.GetError());
     return {};
   }
   return xml::Inflate(&fin, diag, Source(path));
@@ -482,7 +482,7 @@ std::vector<std::unique_ptr<xml::XmlResource>> ResourceFileFlattener::LinkAndVer
 
   if (options_.no_version_vectors || options_.no_version_transitions) {
     // Skip this if it is a vector or animated-vector.
-    xml::Element* el = xml::FindRootElement(doc);
+    xml::Element* el = doc->root.get();
     if (el && el->namespace_uri.empty()) {
       if ((options_.no_version_vectors && IsVectorElement(el->name)) ||
           (options_.no_version_transitions && IsTransitionElement(el->name))) {
@@ -1295,7 +1295,7 @@ class LinkCommand {
       }
 
       for (uint32_t i = 0; i < num_files; i++) {
-        pb::CompiledFile compiled_file;
+        pb::internal::CompiledFile compiled_file;
         if (!input_stream.ReadCompiledFile(&compiled_file)) {
           context_->GetDiagnostics()->Error(DiagMessage(src)
                                             << "failed to read compiled file header");
diff --git a/tools/aapt2/cmd/Util.cpp b/tools/aapt2/cmd/Util.cpp
index e1c45d68f6115..d17858d45d08a 100644
--- a/tools/aapt2/cmd/Util.cpp
+++ b/tools/aapt2/cmd/Util.cpp
@@ -28,7 +28,7 @@
 #include "util/Maybe.h"
 #include "util/Util.h"
 
-using android::StringPiece;
+using ::android::StringPiece;
 
 namespace aapt {
 
@@ -134,19 +134,21 @@ static xml::AaptAttribute CreateAttributeWithId(const ResourceId& id) {
   return xml::AaptAttribute(Attribute(), id);
 }
 
+static xml::NamespaceDecl CreateAndroidNamespaceDecl() {
+  xml::NamespaceDecl decl;
+  decl.prefix = "android";
+  decl.uri = xml::kSchemaAndroid;
+  return decl;
+}
+
 std::unique_ptr<xml::XmlResource> GenerateSplitManifest(const AppInfo& app_info,
                                                         const SplitConstraints& constraints) {
   const ResourceId kVersionCode(0x0101021b);
   const ResourceId kRevisionCode(0x010104d5);
   const ResourceId kHasCode(0x0101000c);
 
-  std::unique_ptr<xml::XmlResource> doc = util::make_unique<xml::XmlResource>();
-
-  std::unique_ptr<xml::Namespace> namespace_android = util::make_unique<xml::Namespace>();
-  namespace_android->namespace_uri = xml::kSchemaAndroid;
-  namespace_android->namespace_prefix = "android";
-
   std::unique_ptr<xml::Element> manifest_el = util::make_unique<xml::Element>();
+  manifest_el->namespace_decls.push_back(CreateAndroidNamespaceDecl());
   manifest_el->name = "manifest";
   manifest_el->attributes.push_back(xml::Attribute{"", "package", app_info.package});
 
@@ -179,8 +181,8 @@ std::unique_ptr<xml::XmlResource> GenerateSplitManifest(const AppInfo& app_info,
         xml::Attribute{"", "configForSplit", app_info.split_name.value()});
   }
 
-  // Splits may contain more configurations than originally desired (fallback densities, etc.).
-  // This makes programmatic discovery of split targetting difficult. Encode the original
+  // Splits may contain more configurations than originally desired (fall-back densities, etc.).
+  // This makes programmatic discovery of split targeting difficult. Encode the original
   // split constraints intended for this split.
   std::stringstream target_config_str;
   target_config_str << util::Joiner(constraints.configs, ",");
@@ -193,8 +195,9 @@ std::unique_ptr<xml::XmlResource> GenerateSplitManifest(const AppInfo& app_info,
                      util::make_unique<BinaryPrimitive>(android::Res_value::TYPE_INT_BOOLEAN, 0u)});
 
   manifest_el->AppendChild(std::move(application_el));
-  namespace_android->AppendChild(std::move(manifest_el));
-  doc->root = std::move(namespace_android);
+
+  std::unique_ptr<xml::XmlResource> doc = util::make_unique<xml::XmlResource>();
+  doc->root = std::move(manifest_el);
   return doc;
 }
 
@@ -284,7 +287,7 @@ static Maybe<int> ExtractSdkVersion(xml::Attribute* attr, std::string* out_error
 
 Maybe<AppInfo> ExtractAppInfoFromBinaryManifest(xml::XmlResource* xml_res, IDiagnostics* diag) {
   // Make sure the first element is <manifest> with package attribute.
-  xml::Element* manifest_el = xml::FindRootElement(xml_res->root.get());
+  xml::Element* manifest_el = xml_res->root.get();
   if (manifest_el == nullptr) {
     return {};
   }
diff --git a/tools/aapt2/compile/InlineXmlFormatParser.cpp b/tools/aapt2/compile/InlineXmlFormatParser.cpp
index 786494b6ad1c3..857cdd5365a0c 100644
--- a/tools/aapt2/compile/InlineXmlFormatParser.cpp
+++ b/tools/aapt2/compile/InlineXmlFormatParser.cpp
@@ -16,12 +16,8 @@
 
 #include "compile/InlineXmlFormatParser.h"
 
-#include <sstream>
 #include <string>
 
-#include "android-base/macros.h"
-
-#include "Debug.h"
 #include "ResourceUtils.h"
 #include "util/Util.h"
 #include "xml/XmlDom.h"
@@ -31,19 +27,17 @@ namespace aapt {
 
 namespace {
 
-/**
- * XML Visitor that will find all <aapt:attr> elements for extraction.
- */
+struct InlineDeclaration {
+  xml::Element* el;
+  std::string attr_namespace_uri;
+  std::string attr_name;
+};
+
+// XML Visitor that will find all <aapt:attr> elements for extraction.
 class Visitor : public xml::PackageAwareVisitor {
  public:
   using xml::PackageAwareVisitor::Visit;
 
-  struct InlineDeclaration {
-    xml::Element* el;
-    std::string attr_namespace_uri;
-    std::string attr_name;
-  };
-
   explicit Visitor(IAaptContext* context, xml::XmlResource* xml_resource)
       : context_(context), xml_resource_(xml_resource) {}
 
@@ -53,51 +47,44 @@ class Visitor : public xml::PackageAwareVisitor {
       return;
     }
 
-    const Source& src = xml_resource_->file.source.WithLine(el->line_number);
+    const Source src = xml_resource_->file.source.WithLine(el->line_number);
 
     xml::Attribute* attr = el->FindAttribute({}, "name");
     if (!attr) {
-      context_->GetDiagnostics()->Error(DiagMessage(src)
-                                        << "missing 'name' attribute");
+      context_->GetDiagnostics()->Error(DiagMessage(src) << "missing 'name' attribute");
       error_ = true;
       return;
     }
 
     Maybe<Reference> ref = ResourceUtils::ParseXmlAttributeName(attr->value);
     if (!ref) {
-      context_->GetDiagnostics()->Error(
-          DiagMessage(src) << "invalid XML attribute '" << attr->value << "'");
+      context_->GetDiagnostics()->Error(DiagMessage(src) << "invalid XML attribute '" << attr->value
+                                                         << "'");
       error_ = true;
       return;
     }
 
     const ResourceName& name = ref.value().name.value();
 
-    // Use an empty string for the compilation package because we don't want to
-    // default to
-    // the local package if the user specified name="style" or something. This
-    // should just
+    // Use an empty string for the compilation package because we don't want to default to
+    // the local package if the user specified name="style" or something. This should just
     // be the default namespace.
-    Maybe<xml::ExtractedPackage> maybe_pkg =
-        TransformPackageAlias(name.package, {});
+    Maybe<xml::ExtractedPackage> maybe_pkg = TransformPackageAlias(name.package, {});
     if (!maybe_pkg) {
-      context_->GetDiagnostics()->Error(DiagMessage(src)
-                                        << "invalid namespace prefix '"
-                                        << name.package << "'");
+      context_->GetDiagnostics()->Error(DiagMessage(src) << "invalid namespace prefix '"
+                                                         << name.package << "'");
       error_ = true;
       return;
     }
 
     const xml::ExtractedPackage& pkg = maybe_pkg.value();
-    const bool private_namespace =
-        pkg.private_namespace || ref.value().private_reference;
+    const bool private_namespace = pkg.private_namespace || ref.value().private_reference;
 
     InlineDeclaration decl;
     decl.el = el;
     decl.attr_name = name.entry;
     if (!pkg.package.empty()) {
-      decl.attr_namespace_uri =
-          xml::BuildPackageNamespace(pkg.package, private_namespace);
+      decl.attr_namespace_uri = xml::BuildPackageNamespace(pkg.package, private_namespace);
     }
 
     inline_declarations_.push_back(std::move(decl));
@@ -107,7 +94,9 @@ class Visitor : public xml::PackageAwareVisitor {
     return inline_declarations_;
   }
 
-  bool HasError() const { return error_; }
+  bool HasError() const {
+    return error_;
+  }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(Visitor);
@@ -120,8 +109,7 @@ class Visitor : public xml::PackageAwareVisitor {
 
 }  // namespace
 
-bool InlineXmlFormatParser::Consume(IAaptContext* context,
-                                    xml::XmlResource* doc) {
+bool InlineXmlFormatParser::Consume(IAaptContext* context, xml::XmlResource* doc) {
   Visitor visitor(context, doc);
   doc->root->Accept(&visitor);
   if (visitor.HasError()) {
@@ -129,69 +117,53 @@ bool InlineXmlFormatParser::Consume(IAaptContext* context,
   }
 
   size_t name_suffix_counter = 0;
-  for (const Visitor::InlineDeclaration& decl :
-       visitor.GetInlineDeclarations()) {
+  for (const InlineDeclaration& decl : visitor.GetInlineDeclarations()) {
     auto new_doc = util::make_unique<xml::XmlResource>();
     new_doc->file.config = doc->file.config;
     new_doc->file.source = doc->file.source.WithLine(decl.el->line_number);
     new_doc->file.name = doc->file.name;
 
     // Modify the new entry name. We need to suffix the entry with a number to
-    // avoid
-    // local collisions, then mangle it with the empty package, such that it
-    // won't show up
+    // avoid local collisions, then mangle it with the empty package, such that it won't show up
     // in R.java.
-
-    new_doc->file.name.entry =
-        NameMangler::MangleEntry({}, new_doc->file.name.entry + "__" +
-                                         std::to_string(name_suffix_counter));
+    new_doc->file.name.entry = NameMangler::MangleEntry(
+        {}, new_doc->file.name.entry + "__" + std::to_string(name_suffix_counter));
 
     // Extracted elements must be the only child of <aapt:attr>.
     // Make sure there is one root node in the children (ignore empty text).
-    for (auto& child : decl.el->children) {
+    for (std::unique_ptr<xml::Node>& child : decl.el->children) {
       const Source child_source = doc->file.source.WithLine(child->line_number);
       if (xml::Text* t = xml::NodeCast<xml::Text>(child.get())) {
         if (!util::TrimWhitespace(t->text).empty()) {
-          context->GetDiagnostics()->Error(
-              DiagMessage(child_source)
-              << "can't extract text into its own resource");
+          context->GetDiagnostics()->Error(DiagMessage(child_source)
+                                           << "can't extract text into its own resource");
           return false;
         }
       } else if (new_doc->root) {
-        context->GetDiagnostics()->Error(
-            DiagMessage(child_source)
-            << "inline XML resources must have a single root");
+        context->GetDiagnostics()->Error(DiagMessage(child_source)
+                                         << "inline XML resources must have a single root");
         return false;
       } else {
-        new_doc->root = std::move(child);
+        new_doc->root.reset(static_cast<xml::Element*>(child.release()));
         new_doc->root->parent = nullptr;
       }
     }
 
-    // Walk up and find the parent element.
-    xml::Node* node = decl.el;
-    xml::Element* parent_el = nullptr;
-    while (node->parent &&
-           (parent_el = xml::NodeCast<xml::Element>(node->parent)) == nullptr) {
-      node = node->parent;
-    }
-
+    // Get the parent element of <aapt:attr>
+    xml::Element* parent_el = decl.el->parent;
     if (!parent_el) {
-      context->GetDiagnostics()->Error(
-          DiagMessage(new_doc->file.source)
-          << "no suitable parent for inheriting attribute");
+      context->GetDiagnostics()->Error(DiagMessage(new_doc->file.source)
+                                       << "no suitable parent for inheriting attribute");
       return false;
     }
 
     // Add the inline attribute to the parent.
-    parent_el->attributes.push_back(
-        xml::Attribute{decl.attr_namespace_uri, decl.attr_name,
-                       "@" + new_doc->file.name.ToString()});
+    parent_el->attributes.push_back(xml::Attribute{decl.attr_namespace_uri, decl.attr_name,
+                                                   "@" + new_doc->file.name.ToString()});
 
     // Delete the subtree.
-    for (auto iter = parent_el->children.begin();
-         iter != parent_el->children.end(); ++iter) {
-      if (iter->get() == node) {
+    for (auto iter = parent_el->children.begin(); iter != parent_el->children.end(); ++iter) {
+      if (iter->get() == decl.el) {
         parent_el->children.erase(iter);
         break;
       }
diff --git a/tools/aapt2/compile/InlineXmlFormatParser.h b/tools/aapt2/compile/InlineXmlFormatParser.h
index 1a658fd6a1808..4300023e77267 100644
--- a/tools/aapt2/compile/InlineXmlFormatParser.h
+++ b/tools/aapt2/compile/InlineXmlFormatParser.h
@@ -26,35 +26,30 @@
 
 namespace aapt {
 
-/**
- * Extracts Inline XML definitions into their own xml::XmlResource objects.
- *
- * Inline XML looks like:
- *
- * <animated-vector xmlns:android="http://schemas.android.com/apk/res/android"
- *                  xmlns:aapt="http://schemas.android.com/aapt" >
- *   <aapt:attr name="android:drawable" >
- *     <vector
- *       android:height="64dp"
- *       android:width="64dp"
- *       android:viewportHeight="600"
- *       android:viewportWidth="600"/>
- *   </aapt:attr>
- * </animated-vector>
- *
- * The <vector> will be extracted into its own XML file and <animated-vector>
- * will
- * gain an attribute 'android:drawable' set to a reference to the extracted
- * <vector> resource.
- */
+// Extracts Inline XML definitions into their own xml::XmlResource objects.
+//
+// Inline XML looks like:
+//
+// <animated-vector xmlns:android="http://schemas.android.com/apk/res/android"
+//                  xmlns:aapt="http://schemas.android.com/aapt" >
+//   <aapt:attr name="android:drawable" >
+//     <vector
+//       android:height="64dp"
+//       android:width="64dp"
+//       android:viewportHeight="600"
+//       android:viewportWidth="600"/>
+//   </aapt:attr>
+// </animated-vector>
+//
+// The <vector> will be extracted into its own XML file and <animated-vector> will
+// gain an attribute 'android:drawable' set to a reference to the extracted <vector> resource.
 class InlineXmlFormatParser : public IXmlResourceConsumer {
  public:
   explicit InlineXmlFormatParser() = default;
 
   bool Consume(IAaptContext* context, xml::XmlResource* doc) override;
 
-  std::vector<std::unique_ptr<xml::XmlResource>>&
-  GetExtractedInlineXmlDocuments() {
+  std::vector<std::unique_ptr<xml::XmlResource>>& GetExtractedInlineXmlDocuments() {
     return queue_;
   }
 
diff --git a/tools/aapt2/compile/InlineXmlFormatParser_test.cpp b/tools/aapt2/compile/InlineXmlFormatParser_test.cpp
index 348796c98c227..de7739ada407a 100644
--- a/tools/aapt2/compile/InlineXmlFormatParser_test.cpp
+++ b/tools/aapt2/compile/InlineXmlFormatParser_test.cpp
@@ -18,25 +18,32 @@
 
 #include "test/Test.h"
 
+using ::testing::Eq;
+using ::testing::IsNull;
+using ::testing::Not;
+using ::testing::NotNull;
+using ::testing::SizeIs;
+using ::testing::StrEq;
+
 namespace aapt {
 
 TEST(InlineXmlFormatParserTest, PassThrough) {
   std::unique_ptr<IAaptContext> context = test::ContextBuilder().Build();
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"EOF(
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"(
       <View xmlns:android="http://schemas.android.com/apk/res/android">
         <View android:text="hey">
           <View android:id="hi" />
         </View>
-      </View>)EOF");
+      </View>)");
 
   InlineXmlFormatParser parser;
   ASSERT_TRUE(parser.Consume(context.get(), doc.get()));
-  EXPECT_EQ(0u, parser.GetExtractedInlineXmlDocuments().size());
+  EXPECT_THAT(parser.GetExtractedInlineXmlDocuments(), SizeIs(0u));
 }
 
 TEST(InlineXmlFormatParserTest, ExtractOneXmlResource) {
   std::unique_ptr<IAaptContext> context = test::ContextBuilder().Build();
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"EOF(
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"(
       <View1 xmlns:android="http://schemas.android.com/apk/res/android"
             xmlns:aapt="http://schemas.android.com/aapt">
         <aapt:attr name="android:text">
@@ -44,7 +51,7 @@ TEST(InlineXmlFormatParserTest, ExtractOneXmlResource) {
             <View3 android:id="hi" />
           </View2>
         </aapt:attr>
-      </View1>)EOF");
+      </View1>)");
 
   doc->file.name = test::ParseNameOrDie("layout/main");
 
@@ -52,42 +59,38 @@ TEST(InlineXmlFormatParserTest, ExtractOneXmlResource) {
   ASSERT_TRUE(parser.Consume(context.get(), doc.get()));
 
   // One XML resource should have been extracted.
-  EXPECT_EQ(1u, parser.GetExtractedInlineXmlDocuments().size());
+  EXPECT_THAT(parser.GetExtractedInlineXmlDocuments(), SizeIs(1u));
 
-  xml::Element* el = xml::FindRootElement(doc.get());
-  ASSERT_NE(nullptr, el);
-
-  EXPECT_EQ("View1", el->name);
+  xml::Element* el = doc->root.get();
+  ASSERT_THAT(el, NotNull());
+  EXPECT_THAT(el->name, StrEq("View1"));
 
   // The <aapt:attr> tag should be extracted.
-  EXPECT_EQ(nullptr, el->FindChild(xml::kSchemaAapt, "attr"));
+  EXPECT_THAT(el->FindChild(xml::kSchemaAapt, "attr"), IsNull());
 
   // The 'android:text' attribute should be set with a reference.
   xml::Attribute* attr = el->FindAttribute(xml::kSchemaAndroid, "text");
-  ASSERT_NE(nullptr, attr);
+  ASSERT_THAT(attr, NotNull());
 
   ResourceNameRef name_ref;
   ASSERT_TRUE(ResourceUtils::ParseReference(attr->value, &name_ref));
 
-  xml::XmlResource* extracted_doc =
-      parser.GetExtractedInlineXmlDocuments()[0].get();
-  ASSERT_NE(nullptr, extracted_doc);
+  xml::XmlResource* extracted_doc = parser.GetExtractedInlineXmlDocuments()[0].get();
+  ASSERT_THAT(extracted_doc, NotNull());
 
   // Make sure the generated reference is correct.
-  EXPECT_EQ(name_ref.package, extracted_doc->file.name.package);
-  EXPECT_EQ(name_ref.type, extracted_doc->file.name.type);
-  EXPECT_EQ(name_ref.entry, extracted_doc->file.name.entry);
+  EXPECT_THAT(extracted_doc->file.name, Eq(name_ref));
 
   // Verify the structure of the extracted XML.
-  el = xml::FindRootElement(extracted_doc);
-  ASSERT_NE(nullptr, el);
-  EXPECT_EQ("View2", el->name);
-  EXPECT_NE(nullptr, el->FindChild({}, "View3"));
+  el = extracted_doc->root.get();
+  ASSERT_THAT(el, NotNull());
+  EXPECT_THAT(el->name, StrEq("View2"));
+  EXPECT_THAT(el->FindChild({}, "View3"), NotNull());
 }
 
 TEST(InlineXmlFormatParserTest, ExtractTwoXmlResources) {
   std::unique_ptr<IAaptContext> context = test::ContextBuilder().Build();
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"EOF(
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"(
       <View1 xmlns:android="http://schemas.android.com/apk/res/android"
             xmlns:aapt="http://schemas.android.com/aapt">
         <aapt:attr name="android:text">
@@ -99,45 +102,39 @@ TEST(InlineXmlFormatParserTest, ExtractTwoXmlResources) {
         <aapt:attr name="android:drawable">
           <vector />
         </aapt:attr>
-      </View1>)EOF");
+      </View1>)");
 
   doc->file.name = test::ParseNameOrDie("layout/main");
 
   InlineXmlFormatParser parser;
   ASSERT_TRUE(parser.Consume(context.get(), doc.get()));
-  ASSERT_EQ(2u, parser.GetExtractedInlineXmlDocuments().size());
+  ASSERT_THAT(parser.GetExtractedInlineXmlDocuments(), SizeIs(2u));
 
-  xml::Element* el = xml::FindRootElement(doc.get());
-  ASSERT_NE(nullptr, el);
-
-  EXPECT_EQ("View1", el->name);
+  xml::Element* el = doc->root.get();
+  ASSERT_THAT(el, NotNull());
+  EXPECT_THAT(el->name, StrEq("View1"));
 
   xml::Attribute* attr_text = el->FindAttribute(xml::kSchemaAndroid, "text");
-  ASSERT_NE(nullptr, attr_text);
+  ASSERT_THAT(attr_text, NotNull());
 
-  xml::Attribute* attr_drawable =
-      el->FindAttribute(xml::kSchemaAndroid, "drawable");
-  ASSERT_NE(nullptr, attr_drawable);
+  xml::Attribute* attr_drawable = el->FindAttribute(xml::kSchemaAndroid, "drawable");
+  ASSERT_THAT(attr_drawable, NotNull());
 
   // The two extracted resources should have different names.
-  EXPECT_NE(attr_text->value, attr_drawable->value);
+  EXPECT_THAT(attr_text->value, Not(Eq(attr_drawable->value)));
 
   // The child <aapt:attr> elements should be gone.
-  EXPECT_EQ(nullptr, el->FindChild(xml::kSchemaAapt, "attr"));
+  EXPECT_THAT(el->FindChild(xml::kSchemaAapt, "attr"), IsNull());
 
-  xml::XmlResource* extracted_doc_text =
-      parser.GetExtractedInlineXmlDocuments()[0].get();
-  ASSERT_NE(nullptr, extracted_doc_text);
-  el = xml::FindRootElement(extracted_doc_text);
-  ASSERT_NE(nullptr, el);
-  EXPECT_EQ("View2", el->name);
+  xml::XmlResource* extracted_doc_text = parser.GetExtractedInlineXmlDocuments()[0].get();
+  ASSERT_THAT(extracted_doc_text, NotNull());
+  ASSERT_THAT(extracted_doc_text->root, NotNull());
+  EXPECT_THAT(extracted_doc_text->root->name, StrEq("View2"));
 
-  xml::XmlResource* extracted_doc_drawable =
-      parser.GetExtractedInlineXmlDocuments()[1].get();
-  ASSERT_NE(nullptr, extracted_doc_drawable);
-  el = xml::FindRootElement(extracted_doc_drawable);
-  ASSERT_NE(nullptr, el);
-  EXPECT_EQ("vector", el->name);
+  xml::XmlResource* extracted_doc_drawable = parser.GetExtractedInlineXmlDocuments()[1].get();
+  ASSERT_THAT(extracted_doc_drawable, NotNull());
+  ASSERT_THAT(extracted_doc_drawable->root, NotNull());
+  EXPECT_THAT(extracted_doc_drawable->root->name, StrEq("vector"));
 }
 
 }  // namespace aapt
diff --git a/tools/aapt2/configuration/ConfigurationParser.cpp b/tools/aapt2/configuration/ConfigurationParser.cpp
index d051120b9445d..bdccf8bcae3a3 100644
--- a/tools/aapt2/configuration/ConfigurationParser.cpp
+++ b/tools/aapt2/configuration/ConfigurationParser.cpp
@@ -22,13 +22,14 @@
 #include <memory>
 #include <utility>
 
-#include <android-base/file.h>
-#include <android-base/logging.h>
+#include "android-base/file.h"
+#include "android-base/logging.h"
 
 #include "ConfigDescription.h"
 #include "Diagnostics.h"
 #include "io/File.h"
 #include "io/FileSystem.h"
+#include "io/StringInputStream.h"
 #include "util/Maybe.h"
 #include "util/Util.h"
 #include "xml/XmlActionExecutor.h"
@@ -49,9 +50,9 @@ using ::aapt::configuration::Group;
 using ::aapt::configuration::Locale;
 using ::aapt::io::IFile;
 using ::aapt::io::RegularFile;
+using ::aapt::io::StringInputStream;
 using ::aapt::util::TrimWhitespace;
 using ::aapt::xml::Element;
-using ::aapt::xml::FindRootElement;
 using ::aapt::xml::NodeCast;
 using ::aapt::xml::XmlActionExecutor;
 using ::aapt::xml::XmlActionExecutorPolicy;
@@ -182,15 +183,14 @@ ConfigurationParser::ConfigurationParser(std::string contents)
 }
 
 Maybe<PostProcessingConfiguration> ConfigurationParser::Parse() {
-  std::istringstream in(contents_);
-
-  auto doc = xml::Inflate(&in, diag_, Source("config.xml"));
+  StringInputStream in(contents_);
+  std::unique_ptr<xml::XmlResource> doc = xml::Inflate(&in, diag_, Source("config.xml"));
   if (!doc) {
     return {};
   }
 
   // Strip any namespaces from the XML as the XmlActionExecutor ignores anything with a namespace.
-  auto* root = FindRootElement(doc.get());
+  Element* root = doc->root.get();
   if (root == nullptr) {
     diag_->Error(DiagMessage() << "Could not find the root element in the XML document");
     return {};
diff --git a/tools/aapt2/configuration/ConfigurationParser_test.cpp b/tools/aapt2/configuration/ConfigurationParser_test.cpp
index fb71e98d2fb5e..f89773720cc51 100644
--- a/tools/aapt2/configuration/ConfigurationParser_test.cpp
+++ b/tools/aapt2/configuration/ConfigurationParser_test.cpp
@@ -18,9 +18,6 @@
 
 #include <string>
 
-#include <gmock/gmock.h>
-#include <gtest/gtest.h>
-
 #include "androidfw/ResourceTypes.h"
 
 #include "test/Test.h"
@@ -29,7 +26,7 @@
 namespace aapt {
 namespace {
 
-using android::ResTable_config;
+using ::android::ResTable_config;
 using configuration::Abi;
 using configuration::AndroidSdk;
 using configuration::Artifact;
@@ -38,7 +35,7 @@ using configuration::DeviceFeature;
 using configuration::GlTexture;
 using configuration::Locale;
 using configuration::AndroidManifest;
-using testing::ElementsAre;
+using ::testing::ElementsAre;
 using xml::Element;
 using xml::NodeCast;
 
@@ -192,7 +189,7 @@ TEST_F(ConfigurationParserTest, ArtifactAction) {
   auto doc = test::BuildXmlDom(xml);
 
   PostProcessingConfiguration config;
-  bool ok = artifact_handler_(&config, NodeCast<Element>(doc.get()->root.get()), &diag_);
+  bool ok = artifact_handler_(&config, NodeCast<Element>(doc->root.get()), &diag_);
   ASSERT_TRUE(ok);
 
   EXPECT_EQ(1ul, config.artifacts.size());
diff --git a/tools/aapt2/flatten/Archive.cpp b/tools/aapt2/flatten/Archive.cpp
index 826f91b4a2fd1..5f8bd063f9b09 100644
--- a/tools/aapt2/flatten/Archive.cpp
+++ b/tools/aapt2/flatten/Archive.cpp
@@ -23,12 +23,14 @@
 
 #include "android-base/errors.h"
 #include "android-base/macros.h"
+#include "android-base/utf8.h"
 #include "androidfw/StringPiece.h"
 #include "ziparchive/zip_writer.h"
 
 #include "util/Files.h"
 
-using android::StringPiece;
+using ::android::StringPiece;
+using ::android::base::SystemErrorCodeToString;
 
 namespace aapt {
 
@@ -58,11 +60,11 @@ class DirectoryWriter : public IArchiveWriter {
 
     std::string full_path = dir_;
     file::AppendPath(&full_path, path);
-    file::mkdirs(file::GetStem(full_path));
+    file::mkdirs(file::GetStem(full_path).to_string());
 
-    file_ = {fopen(full_path.data(), "wb"), fclose};
+    file_ = {::android::base::utf8::fopen(full_path.c_str(), "wb"), fclose};
     if (!file_) {
-      error_ = android::base::SystemErrorCodeToString(errno);
+      error_ = SystemErrorCodeToString(errno);
       return false;
     }
     return true;
@@ -74,7 +76,7 @@ class DirectoryWriter : public IArchiveWriter {
     }
 
     if (fwrite(data, 1, len, file_.get()) != static_cast<size_t>(len)) {
-      error_ = android::base::SystemErrorCodeToString(errno);
+      error_ = SystemErrorCodeToString(errno);
       file_.reset(nullptr);
       return false;
     }
@@ -121,9 +123,9 @@ class ZipFileWriter : public IArchiveWriter {
   ZipFileWriter() = default;
 
   bool Open(const StringPiece& path) {
-    file_ = {fopen(path.data(), "w+b"), fclose};
+    file_ = {::android::base::utf8::fopen(path.to_string().c_str(), "w+b"), fclose};
     if (!file_) {
-      error_ = android::base::SystemErrorCodeToString(errno);
+      error_ = SystemErrorCodeToString(errno);
       return false;
     }
     writer_ = util::make_unique<ZipWriter>(file_.get());
diff --git a/tools/aapt2/flatten/TableFlattener.cpp b/tools/aapt2/flatten/TableFlattener.cpp
index e5993a65366d6..14b776b1bd994 100644
--- a/tools/aapt2/flatten/TableFlattener.cpp
+++ b/tools/aapt2/flatten/TableFlattener.cpp
@@ -133,7 +133,7 @@ class MapFlattenVisitor : public RawValueVisitor {
   }
 
   void Visit(Array* array) override {
-    for (auto& item : array->items) {
+    for (auto& item : array->elements) {
       ResTable_map* out_entry = buffer_->NextBlock<ResTable_map>();
       FlattenValue(item.get(), out_entry);
       out_entry->value.size = util::HostToDevice16(sizeof(out_entry->value));
diff --git a/tools/aapt2/flatten/XmlFlattener.cpp b/tools/aapt2/flatten/XmlFlattener.cpp
index 331ef784a7da0..b3b308a29fc50 100644
--- a/tools/aapt2/flatten/XmlFlattener.cpp
+++ b/tools/aapt2/flatten/XmlFlattener.cpp
@@ -38,12 +38,10 @@ namespace {
 
 constexpr uint32_t kLowPriority = 0xffffffffu;
 
-static bool cmp_xml_attribute_by_id(const xml::Attribute* a,
-                                    const xml::Attribute* b) {
+static bool cmp_xml_attribute_by_id(const xml::Attribute* a, const xml::Attribute* b) {
   if (a->compiled_attribute && a->compiled_attribute.value().id) {
     if (b->compiled_attribute && b->compiled_attribute.value().id) {
-      return a->compiled_attribute.value().id.value() <
-             b->compiled_attribute.value().id.value();
+      return a->compiled_attribute.value().id.value() < b->compiled_attribute.value().id.value();
     }
     return true;
   } else if (!b->compiled_attribute) {
@@ -75,17 +73,6 @@ class XmlFlattenerVisitor : public xml::Visitor {
   XmlFlattenerVisitor(BigBuffer* buffer, XmlFlattenerOptions options)
       : buffer_(buffer), options_(options) {}
 
-  void Visit(xml::Namespace* node) override {
-    if (node->namespace_uri == xml::kSchemaTools) {
-      // Skip dedicated tools namespace.
-      xml::Visitor::Visit(node);
-    } else {
-      WriteNamespace(node, android::RES_XML_START_NAMESPACE_TYPE);
-      xml::Visitor::Visit(node);
-      WriteNamespace(node, android::RES_XML_END_NAMESPACE_TYPE);
-    }
-  }
-
   void Visit(xml::Text* node) override {
     if (util::TrimWhitespace(node->text).empty()) {
       // Skip whitespace only text nodes.
@@ -93,8 +80,7 @@ class XmlFlattenerVisitor : public xml::Visitor {
     }
 
     ChunkWriter writer(buffer_);
-    ResXMLTree_node* flat_node =
-        writer.StartChunk<ResXMLTree_node>(RES_XML_CDATA_TYPE);
+    ResXMLTree_node* flat_node = writer.StartChunk<ResXMLTree_node>(RES_XML_CDATA_TYPE);
     flat_node->lineNumber = util::HostToDevice32(node->line_number);
     flat_node->comment.index = util::HostToDevice32(-1);
 
@@ -109,6 +95,13 @@ class XmlFlattenerVisitor : public xml::Visitor {
   }
 
   void Visit(xml::Element* node) override {
+    for (const xml::NamespaceDecl& decl : node->namespace_decls) {
+      // Skip dedicated tools namespace.
+      if (decl.uri != xml::kSchemaTools) {
+        WriteNamespace(decl, android::RES_XML_START_NAMESPACE_TYPE);
+      }
+    }
+
     {
       ChunkWriter start_writer(buffer_);
       ResXMLTree_node* flat_node =
@@ -116,19 +109,15 @@ class XmlFlattenerVisitor : public xml::Visitor {
       flat_node->lineNumber = util::HostToDevice32(node->line_number);
       flat_node->comment.index = util::HostToDevice32(-1);
 
-      ResXMLTree_attrExt* flat_elem =
-          start_writer.NextBlock<ResXMLTree_attrExt>();
+      ResXMLTree_attrExt* flat_elem = start_writer.NextBlock<ResXMLTree_attrExt>();
 
-      // A missing namespace must be null, not an empty string. Otherwise the
-      // runtime complains.
+      // A missing namespace must be null, not an empty string. Otherwise the runtime complains.
       AddString(node->namespace_uri, kLowPriority, &flat_elem->ns,
                 true /* treat_empty_string_as_null */);
-      AddString(node->name, kLowPriority, &flat_elem->name,
-                true /* treat_empty_string_as_null */);
+      AddString(node->name, kLowPriority, &flat_elem->name, true /* treat_empty_string_as_null */);
 
       flat_elem->attributeStart = util::HostToDevice16(sizeof(*flat_elem));
-      flat_elem->attributeSize =
-          util::HostToDevice16(sizeof(ResXMLTree_attribute));
+      flat_elem->attributeSize = util::HostToDevice16(sizeof(ResXMLTree_attribute));
 
       WriteAttributes(node, flat_elem, &start_writer);
 
@@ -144,14 +133,20 @@ class XmlFlattenerVisitor : public xml::Visitor {
       flat_end_node->lineNumber = util::HostToDevice32(node->line_number);
       flat_end_node->comment.index = util::HostToDevice32(-1);
 
-      ResXMLTree_endElementExt* flat_end_elem =
-          end_writer.NextBlock<ResXMLTree_endElementExt>();
+      ResXMLTree_endElementExt* flat_end_elem = end_writer.NextBlock<ResXMLTree_endElementExt>();
       AddString(node->namespace_uri, kLowPriority, &flat_end_elem->ns,
                 true /* treat_empty_string_as_null */);
       AddString(node->name, kLowPriority, &flat_end_elem->name);
 
       end_writer.Finish();
     }
+
+    for (auto iter = node->namespace_decls.rbegin(); iter != node->namespace_decls.rend(); ++iter) {
+      // Skip dedicated tools namespace.
+      if (iter->uri != xml::kSchemaTools) {
+        WriteNamespace(*iter, android::RES_XML_END_NAMESPACE_TYPE);
+      }
+    }
   }
 
  private:
@@ -173,16 +168,16 @@ class XmlFlattenerVisitor : public xml::Visitor {
     string_refs.push_back(StringFlattenDest{ref, dest});
   }
 
-  void WriteNamespace(xml::Namespace* node, uint16_t type) {
+  void WriteNamespace(const xml::NamespaceDecl& decl, uint16_t type) {
     ChunkWriter writer(buffer_);
 
     ResXMLTree_node* flatNode = writer.StartChunk<ResXMLTree_node>(type);
-    flatNode->lineNumber = util::HostToDevice32(node->line_number);
+    flatNode->lineNumber = util::HostToDevice32(decl.line_number);
     flatNode->comment.index = util::HostToDevice32(-1);
 
     ResXMLTree_namespaceExt* flat_ns = writer.NextBlock<ResXMLTree_namespaceExt>();
-    AddString(node->namespace_prefix, kLowPriority, &flat_ns->prefix);
-    AddString(node->namespace_uri, kLowPriority, &flat_ns->uri);
+    AddString(decl.prefix, kLowPriority, &flat_ns->prefix);
+    AddString(decl.uri, kLowPriority, &flat_ns->uri);
 
     writer.Finish();
   }
diff --git a/tools/aapt2/integration-tests/AppOne/res/navigation/home.xml b/tools/aapt2/integration-tests/AppOne/res/navigation/home.xml
new file mode 100644
index 0000000000000..ade271d60ab6f
--- /dev/null
+++ b/tools/aapt2/integration-tests/AppOne/res/navigation/home.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<navigation />
diff --git a/tools/aapt2/io/FileInputStream.cpp b/tools/aapt2/io/FileInputStream.cpp
new file mode 100644
index 0000000000000..07dbb5a98add7
--- /dev/null
+++ b/tools/aapt2/io/FileInputStream.cpp
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "io/FileInputStream.h"
+
+#include <errno.h>   // for errno
+#include <fcntl.h>   // for O_RDONLY
+#include <unistd.h>  // for read
+
+#include "android-base/errors.h"
+#include "android-base/file.h"  // for O_BINARY
+#include "android-base/macros.h"
+#include "android-base/utf8.h"
+
+using ::android::base::SystemErrorCodeToString;
+
+namespace aapt {
+namespace io {
+
+FileInputStream::FileInputStream(const std::string& path, size_t buffer_capacity)
+    : FileInputStream(::android::base::utf8::open(path.c_str(), O_RDONLY | O_BINARY),
+                      buffer_capacity) {
+}
+
+FileInputStream::FileInputStream(int fd, size_t buffer_capacity)
+    : fd_(fd),
+      buffer_capacity_(buffer_capacity),
+      buffer_offset_(0u),
+      buffer_size_(0u),
+      total_byte_count_(0u) {
+  if (fd_ == -1) {
+    error_ = SystemErrorCodeToString(errno);
+  } else {
+    buffer_.reset(new uint8_t[buffer_capacity_]);
+  }
+}
+
+bool FileInputStream::Next(const void** data, size_t* size) {
+  if (HadError()) {
+    return false;
+  }
+
+  // Deal with any remaining bytes after BackUp was called.
+  if (buffer_offset_ != buffer_size_) {
+    *data = buffer_.get() + buffer_offset_;
+    *size = buffer_size_ - buffer_offset_;
+    total_byte_count_ += buffer_size_ - buffer_offset_;
+    buffer_offset_ = buffer_size_;
+    return true;
+  }
+
+  ssize_t n = TEMP_FAILURE_RETRY(read(fd_, buffer_.get(), buffer_capacity_));
+  if (n < 0) {
+    error_ = SystemErrorCodeToString(errno);
+    fd_.reset();
+    return false;
+  }
+
+  buffer_size_ = static_cast<size_t>(n);
+  buffer_offset_ = buffer_size_;
+  total_byte_count_ += buffer_size_;
+
+  *data = buffer_.get();
+  *size = buffer_size_;
+  return buffer_size_ != 0u;
+}
+
+void FileInputStream::BackUp(size_t count) {
+  if (count > buffer_offset_) {
+    count = buffer_offset_;
+  }
+  buffer_offset_ -= count;
+  total_byte_count_ -= count;
+}
+
+size_t FileInputStream::ByteCount() const {
+  return total_byte_count_;
+}
+
+bool FileInputStream::HadError() const {
+  return !error_.empty();
+}
+
+std::string FileInputStream::GetError() const {
+  return error_;
+}
+
+}  // namespace io
+}  // namespace aapt
diff --git a/tools/aapt2/io/FileInputStream.h b/tools/aapt2/io/FileInputStream.h
new file mode 100644
index 0000000000000..6beb9a186ce5e
--- /dev/null
+++ b/tools/aapt2/io/FileInputStream.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef AAPT_IO_FILEINPUTSTREAM_H
+#define AAPT_IO_FILEINPUTSTREAM_H
+
+#include "io/Io.h"
+
+#include <memory>
+#include <string>
+
+#include "android-base/macros.h"
+#include "android-base/unique_fd.h"
+
+namespace aapt {
+namespace io {
+
+class FileInputStream : public InputStream {
+ public:
+  explicit FileInputStream(const std::string& path, size_t buffer_capacity = 4096);
+
+  // Takes ownership of `fd`.
+  explicit FileInputStream(int fd, size_t buffer_capacity = 4096);
+
+  bool Next(const void** data, size_t* size) override;
+
+  void BackUp(size_t count) override;
+
+  size_t ByteCount() const override;
+
+  bool HadError() const override;
+
+  std::string GetError() const override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(FileInputStream);
+
+  android::base::unique_fd fd_;
+  std::string error_;
+  std::unique_ptr<uint8_t[]> buffer_;
+  size_t buffer_capacity_;
+  size_t buffer_offset_;
+  size_t buffer_size_;
+  size_t total_byte_count_;
+};
+
+}  // namespace io
+}  // namespace aapt
+
+#endif  // AAPT_IO_FILEINPUTSTREAM_H
diff --git a/tools/aapt2/io/FileInputStream_test.cpp b/tools/aapt2/io/FileInputStream_test.cpp
new file mode 100644
index 0000000000000..7314ab7beebae
--- /dev/null
+++ b/tools/aapt2/io/FileInputStream_test.cpp
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "io/FileInputStream.h"
+
+#include "android-base/macros.h"
+#include "android-base/test_utils.h"
+
+#include "test/Test.h"
+
+using ::android::StringPiece;
+using ::testing::Eq;
+using ::testing::NotNull;
+using ::testing::StrEq;
+
+namespace aapt {
+namespace io {
+
+TEST(FileInputStreamTest, NextAndBackup) {
+  std::string input = "this is a cool string";
+  TemporaryFile file;
+  ASSERT_THAT(TEMP_FAILURE_RETRY(write(file.fd, input.c_str(), input.size())), Eq(21));
+  lseek64(file.fd, 0, SEEK_SET);
+
+  // Use a small buffer size so that we can call Next() a few times.
+  FileInputStream in(file.fd, 10u);
+  ASSERT_FALSE(in.HadError());
+  EXPECT_THAT(in.ByteCount(), Eq(0u));
+
+  const char* buffer;
+  size_t size;
+  ASSERT_TRUE(in.Next(reinterpret_cast<const void**>(&buffer), &size)) << in.GetError();
+  ASSERT_THAT(size, Eq(10u));
+  ASSERT_THAT(buffer, NotNull());
+  EXPECT_THAT(in.ByteCount(), Eq(10u));
+  EXPECT_THAT(StringPiece(buffer, size), Eq("this is a "));
+
+  ASSERT_TRUE(in.Next(reinterpret_cast<const void**>(&buffer), &size));
+  ASSERT_THAT(size, Eq(10u));
+  ASSERT_THAT(buffer, NotNull());
+  EXPECT_THAT(in.ByteCount(), Eq(20u));
+  EXPECT_THAT(StringPiece(buffer, size), Eq("cool strin"));
+
+  in.BackUp(5u);
+  EXPECT_THAT(in.ByteCount(), Eq(15u));
+
+  ASSERT_TRUE(in.Next(reinterpret_cast<const void**>(&buffer), &size));
+  ASSERT_THAT(size, Eq(5u));
+  ASSERT_THAT(buffer, NotNull());
+  ASSERT_THAT(in.ByteCount(), Eq(20u));
+  EXPECT_THAT(StringPiece(buffer, size), Eq("strin"));
+
+  // Backup 1 more than possible. Should clamp.
+  in.BackUp(11u);
+  EXPECT_THAT(in.ByteCount(), Eq(10u));
+
+  ASSERT_TRUE(in.Next(reinterpret_cast<const void**>(&buffer), &size));
+  ASSERT_THAT(size, Eq(10u));
+  ASSERT_THAT(buffer, NotNull());
+  ASSERT_THAT(in.ByteCount(), Eq(20u));
+  EXPECT_THAT(StringPiece(buffer, size), Eq("cool strin"));
+
+  ASSERT_TRUE(in.Next(reinterpret_cast<const void**>(&buffer), &size));
+  ASSERT_THAT(size, Eq(1u));
+  ASSERT_THAT(buffer, NotNull());
+  ASSERT_THAT(in.ByteCount(), Eq(21u));
+  EXPECT_THAT(StringPiece(buffer, size), Eq("g"));
+
+  EXPECT_FALSE(in.Next(reinterpret_cast<const void**>(&buffer), &size));
+  EXPECT_FALSE(in.HadError());
+}
+
+}  // namespace io
+}  // namespace aapt
diff --git a/tools/aapt2/io/StringInputStream.cpp b/tools/aapt2/io/StringInputStream.cpp
new file mode 100644
index 0000000000000..51a18a7d8a9f8
--- /dev/null
+++ b/tools/aapt2/io/StringInputStream.cpp
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "io/StringInputStream.h"
+
+using ::android::StringPiece;
+
+namespace aapt {
+namespace io {
+
+StringInputStream::StringInputStream(const StringPiece& str) : str_(str), offset_(0u) {
+}
+
+bool StringInputStream::Next(const void** data, size_t* size) {
+  if (offset_ == str_.size()) {
+    return false;
+  }
+
+  *data = str_.data() + offset_;
+  *size = str_.size() - offset_;
+  offset_ = str_.size();
+  return true;
+}
+
+void StringInputStream::BackUp(size_t count) {
+  if (count > offset_) {
+    count = offset_;
+  }
+  offset_ -= count;
+}
+
+size_t StringInputStream::ByteCount() const {
+  return offset_;
+}
+
+}  // namespace io
+}  // namespace aapt
diff --git a/tools/aapt2/io/StringInputStream.h b/tools/aapt2/io/StringInputStream.h
new file mode 100644
index 0000000000000..ff5b112ef274a
--- /dev/null
+++ b/tools/aapt2/io/StringInputStream.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef AAPT_IO_STRINGINPUTSTREAM_H
+#define AAPT_IO_STRINGINPUTSTREAM_H
+
+#include "io/Io.h"
+
+#include "android-base/macros.h"
+#include "androidfw/StringPiece.h"
+
+namespace aapt {
+namespace io {
+
+class StringInputStream : public InputStream {
+ public:
+  explicit StringInputStream(const android::StringPiece& str);
+
+  bool Next(const void** data, size_t* size) override;
+
+  void BackUp(size_t count) override;
+
+  size_t ByteCount() const override;
+
+  inline bool HadError() const override {
+    return false;
+  }
+
+  inline std::string GetError() const override {
+    return {};
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(StringInputStream);
+
+  android::StringPiece str_;
+  size_t offset_;
+};
+
+}  // namespace io
+}  // namespace aapt
+
+#endif  // AAPT_IO_STRINGINPUTSTREAM_H
diff --git a/tools/aapt2/io/StringInputStream_test.cpp b/tools/aapt2/io/StringInputStream_test.cpp
new file mode 100644
index 0000000000000..cc57bc498313b
--- /dev/null
+++ b/tools/aapt2/io/StringInputStream_test.cpp
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "io/StringInputStream.h"
+
+#include "test/Test.h"
+
+using ::android::StringPiece;
+using ::testing::Eq;
+using ::testing::NotNull;
+using ::testing::StrEq;
+
+namespace aapt {
+namespace io {
+
+TEST(StringInputStreamTest, OneCallToNextShouldReturnEntireBuffer) {
+  constexpr const size_t kCount = 1000;
+  std::string input;
+  input.resize(kCount, 0x7f);
+  input[0] = 0x00;
+  input[kCount - 1] = 0xff;
+  StringInputStream in(input);
+
+  const char* buffer;
+  size_t size;
+  ASSERT_TRUE(in.Next(reinterpret_cast<const void**>(&buffer), &size));
+  ASSERT_THAT(size, Eq(kCount));
+  ASSERT_THAT(buffer, NotNull());
+
+  EXPECT_THAT(buffer[0], Eq(0x00));
+  EXPECT_THAT(buffer[kCount - 1], Eq('\xff'));
+
+  EXPECT_FALSE(in.Next(reinterpret_cast<const void**>(&buffer), &size));
+  EXPECT_FALSE(in.HadError());
+}
+
+TEST(StringInputStreamTest, BackUp) {
+  std::string input = "hello this is a string";
+  StringInputStream in(input);
+
+  const char* buffer;
+  size_t size;
+  ASSERT_TRUE(in.Next(reinterpret_cast<const void**>(&buffer), &size));
+  ASSERT_THAT(size, Eq(input.size()));
+  ASSERT_THAT(buffer, NotNull());
+  EXPECT_THAT(in.ByteCount(), Eq(input.size()));
+
+  in.BackUp(6u);
+  EXPECT_THAT(in.ByteCount(), Eq(input.size() - 6u));
+
+  ASSERT_TRUE(in.Next(reinterpret_cast<const void**>(&buffer), &size));
+  ASSERT_THAT(size, Eq(6u));
+  ASSERT_THAT(buffer, NotNull());
+  ASSERT_THAT(buffer, StrEq("string"));
+  EXPECT_THAT(in.ByteCount(), Eq(input.size()));
+}
+
+}  // namespace io
+}  // namespace aapt
diff --git a/tools/aapt2/java/ClassDefinition.cpp b/tools/aapt2/java/ClassDefinition.cpp
index 0cec9ae407f59..d7508d257db46 100644
--- a/tools/aapt2/java/ClassDefinition.cpp
+++ b/tools/aapt2/java/ClassDefinition.cpp
@@ -39,6 +39,17 @@ void MethodDefinition::WriteToStream(const StringPiece& prefix, bool final,
   *out << prefix << "}";
 }
 
+ClassDefinition::Result ClassDefinition::AddMember(std::unique_ptr<ClassMember> member) {
+  Result result = Result::kAdded;
+  auto iter = members_.find(member);
+  if (iter != members_.end()) {
+    members_.erase(iter);
+    result = Result::kOverridden;
+  }
+  members_.insert(std::move(member));
+  return result;
+}
+
 bool ClassDefinition::empty() const {
   for (const std::unique_ptr<ClassMember>& member : members_) {
     if (!member->empty()) {
diff --git a/tools/aapt2/java/ClassDefinition.h b/tools/aapt2/java/ClassDefinition.h
index ca76421390d6a..6c4bcad83d2ab 100644
--- a/tools/aapt2/java/ClassDefinition.h
+++ b/tools/aapt2/java/ClassDefinition.h
@@ -18,6 +18,7 @@
 #define AAPT_JAVA_CLASSDEFINITION_H
 
 #include <ostream>
+#include <set>
 #include <string>
 
 #include "android-base/macros.h"
@@ -37,10 +38,14 @@ class ClassMember {
  public:
   virtual ~ClassMember() = default;
 
-  AnnotationProcessor* GetCommentBuilder() { return &processor_; }
+  AnnotationProcessor* GetCommentBuilder() {
+    return &processor_;
+  }
 
   virtual bool empty() const = 0;
 
+  virtual const std::string& GetName() const = 0;
+
   // Writes the class member to the out stream. Subclasses should derive this method
   // to write their own data. Call this base method from the subclass to write out
   // this member's comments/annotations.
@@ -57,7 +62,13 @@ class PrimitiveMember : public ClassMember {
   PrimitiveMember(const android::StringPiece& name, const T& val)
       : name_(name.to_string()), val_(val) {}
 
-  bool empty() const override { return false; }
+  bool empty() const override {
+    return false;
+  }
+
+  const std::string& GetName() const override {
+    return name_;
+  }
 
   void WriteToStream(const android::StringPiece& prefix, bool final,
                      std::ostream* out) const override {
@@ -83,7 +94,13 @@ class PrimitiveMember<std::string> : public ClassMember {
   PrimitiveMember(const android::StringPiece& name, const std::string& val)
       : name_(name.to_string()), val_(val) {}
 
-  bool empty() const override { return false; }
+  bool empty() const override {
+    return false;
+  }
+
+  const std::string& GetName() const override {
+    return name_;
+  }
 
   void WriteToStream(const android::StringPiece& prefix, bool final,
                      std::ostream* out) const override {
@@ -109,9 +126,17 @@ class PrimitiveArrayMember : public ClassMember {
  public:
   explicit PrimitiveArrayMember(const android::StringPiece& name) : name_(name.to_string()) {}
 
-  void AddElement(const T& val) { elements_.push_back(val); }
+  void AddElement(const T& val) {
+    elements_.push_back(val);
+  }
 
-  bool empty() const override { return false; }
+  bool empty() const override {
+    return false;
+  }
+
+  const std::string& GetName() const override {
+    return name_;
+  }
 
   void WriteToStream(const android::StringPiece& prefix, bool final,
                      std::ostream* out) const override {
@@ -154,6 +179,11 @@ class MethodDefinition : public ClassMember {
   // formatting may be broken.
   void AppendStatement(const android::StringPiece& statement);
 
+  // Not quite the same as a name, but good enough.
+  const std::string& GetName() const override {
+    return signature_;
+  }
+
   // Even if the method is empty, we always want to write the method signature.
   bool empty() const override { return false; }
 
@@ -175,19 +205,34 @@ class ClassDefinition : public ClassMember {
   ClassDefinition(const android::StringPiece& name, ClassQualifier qualifier, bool createIfEmpty)
       : name_(name.to_string()), qualifier_(qualifier), create_if_empty_(createIfEmpty) {}
 
-  void AddMember(std::unique_ptr<ClassMember> member) {
-    members_.push_back(std::move(member));
-  }
+  enum class Result {
+    kAdded,
+    kOverridden,
+  };
+
+  Result AddMember(std::unique_ptr<ClassMember> member);
 
   bool empty() const override;
+
+  const std::string& GetName() const override {
+    return name_;
+  }
+
   void WriteToStream(const android::StringPiece& prefix, bool final,
                      std::ostream* out) const override;
 
  private:
+  struct ClassMemberCompare {
+    using T = std::unique_ptr<ClassMember>;
+    bool operator()(const T& a, const T& b) const {
+      return a->GetName() < b->GetName();
+    }
+  };
+
   std::string name_;
   ClassQualifier qualifier_;
   bool create_if_empty_;
-  std::vector<std::unique_ptr<ClassMember>> members_;
+  std::set<std::unique_ptr<ClassMember>, ClassMemberCompare> members_;
 
   DISALLOW_COPY_AND_ASSIGN(ClassDefinition);
 };
diff --git a/tools/aapt2/java/ManifestClassGenerator.cpp b/tools/aapt2/java/ManifestClassGenerator.cpp
index f49e4985fcf19..cad4c6c7c94fd 100644
--- a/tools/aapt2/java/ManifestClassGenerator.cpp
+++ b/tools/aapt2/java/ManifestClassGenerator.cpp
@@ -81,7 +81,10 @@ static bool WriteSymbol(const Source& source, IDiagnostics* diag,
       util::make_unique<StringMember>(result.value(), attr->value);
   string_member->GetCommentBuilder()->AppendComment(el->comment);
 
-  class_def->AddMember(std::move(string_member));
+  if (class_def->AddMember(std::move(string_member)) == ClassDefinition::Result::kOverridden) {
+    diag->Warn(DiagMessage(source.WithLine(el->line_number))
+               << "duplicate definitions of '" << result.value() << "', overriding previous");
+  }
   return true;
 }
 
diff --git a/tools/aapt2/java/ManifestClassGenerator_test.cpp b/tools/aapt2/java/ManifestClassGenerator_test.cpp
index 9f6ec210a6a74..44b6a1ffd5aee 100644
--- a/tools/aapt2/java/ManifestClassGenerator_test.cpp
+++ b/tools/aapt2/java/ManifestClassGenerator_test.cpp
@@ -112,6 +112,21 @@ TEST(ManifestClassGeneratorTest, CommentsAndAnnotationsArePresent) {
   EXPECT_THAT(actual, HasSubstr(expected_secret));
 }
 
+// This is bad but part of public API behaviour so we need to preserve it.
+TEST(ManifestClassGeneratorTest, LastSeenPermissionWithSameLeafNameTakesPrecedence) {
+  std::unique_ptr<IAaptContext> context = test::ContextBuilder().Build();
+  std::unique_ptr<xml::XmlResource> manifest = test::BuildXmlDom(R"(
+      <manifest xmlns:android="http://schemas.android.com/apk/res/android">
+        <permission android:name="android.permission.ACCESS_INTERNET" />
+        <permission android:name="com.android.aapt.test.ACCESS_INTERNET" />
+      </manifest>)");
+
+  std::string actual;
+  ASSERT_TRUE(GetManifestClassText(context.get(), manifest.get(), &actual));
+  EXPECT_THAT(actual, HasSubstr("ACCESS_INTERNET=\"com.android.aapt.test.ACCESS_INTERNET\";"));
+  EXPECT_THAT(actual, Not(HasSubstr("ACCESS_INTERNET=\"android.permission.ACCESS_INTERNET\";")));
+}
+
 static ::testing::AssertionResult GetManifestClassText(IAaptContext* context, xml::XmlResource* res,
                                                        std::string* out_str) {
   std::unique_ptr<ClassDefinition> manifest_class =
diff --git a/tools/aapt2/java/ProguardRules.cpp b/tools/aapt2/java/ProguardRules.cpp
index 5f61faeeebe75..10c46101123cc 100644
--- a/tools/aapt2/java/ProguardRules.cpp
+++ b/tools/aapt2/java/ProguardRules.cpp
@@ -29,18 +29,12 @@ namespace proguard {
 
 class BaseVisitor : public xml::Visitor {
  public:
-  BaseVisitor(const Source& source, KeepSet* keep_set)
-      : source_(source), keep_set_(keep_set) {}
+  using xml::Visitor::Visit;
 
-  virtual void Visit(xml::Text*) override{};
-
-  virtual void Visit(xml::Namespace* node) override {
-    for (const auto& child : node->children) {
-      child->Accept(this);
-    }
+  BaseVisitor(const Source& source, KeepSet* keep_set) : source_(source), keep_set_(keep_set) {
   }
 
-  virtual void Visit(xml::Element* node) override {
+  void Visit(xml::Element* node) override {
     if (!node->namespace_uri.empty()) {
       Maybe<xml::ExtractedPackage> maybe_package =
           xml::ExtractPackageFromNamespace(node->namespace_uri);
@@ -78,10 +72,10 @@ class BaseVisitor : public xml::Visitor {
 
 class LayoutVisitor : public BaseVisitor {
  public:
-  LayoutVisitor(const Source& source, KeepSet* keep_set)
-      : BaseVisitor(source, keep_set) {}
+  LayoutVisitor(const Source& source, KeepSet* keep_set) : BaseVisitor(source, keep_set) {
+  }
 
-  virtual void Visit(xml::Element* node) override {
+  void Visit(xml::Element* node) override {
     bool check_class = false;
     bool check_name = false;
     if (node->namespace_uri.empty()) {
@@ -119,7 +113,7 @@ class MenuVisitor : public BaseVisitor {
   MenuVisitor(const Source& source, KeepSet* keep_set) : BaseVisitor(source, keep_set) {
   }
 
-  virtual void Visit(xml::Element* node) override {
+  void Visit(xml::Element* node) override {
     if (node->namespace_uri.empty() && node->name == "item") {
       for (const auto& attr : node->attributes) {
         if (attr.namespace_uri == xml::kSchemaAndroid) {
@@ -142,10 +136,10 @@ class MenuVisitor : public BaseVisitor {
 
 class XmlResourceVisitor : public BaseVisitor {
  public:
-  XmlResourceVisitor(const Source& source, KeepSet* keep_set)
-      : BaseVisitor(source, keep_set) {}
+  XmlResourceVisitor(const Source& source, KeepSet* keep_set) : BaseVisitor(source, keep_set) {
+  }
 
-  virtual void Visit(xml::Element* node) override {
+  void Visit(xml::Element* node) override {
     bool check_fragment = false;
     if (node->namespace_uri.empty()) {
       check_fragment =
@@ -169,13 +163,12 @@ class XmlResourceVisitor : public BaseVisitor {
 
 class TransitionVisitor : public BaseVisitor {
  public:
-  TransitionVisitor(const Source& source, KeepSet* keep_set)
-      : BaseVisitor(source, keep_set) {}
+  TransitionVisitor(const Source& source, KeepSet* keep_set) : BaseVisitor(source, keep_set) {
+  }
 
-  virtual void Visit(xml::Element* node) override {
+  void Visit(xml::Element* node) override {
     bool check_class =
-        node->namespace_uri.empty() &&
-        (node->name == "transition" || node->name == "pathMotion");
+        node->namespace_uri.empty() && (node->name == "transition" || node->name == "pathMotion");
     if (check_class) {
       xml::Attribute* attr = node->FindAttribute({}, "class");
       if (attr && util::IsJavaClassName(attr->value)) {
@@ -195,7 +188,7 @@ class ManifestVisitor : public BaseVisitor {
   ManifestVisitor(const Source& source, KeepSet* keep_set, bool main_dex_only)
       : BaseVisitor(source, keep_set), main_dex_only_(main_dex_only) {}
 
-  virtual void Visit(xml::Element* node) override {
+  void Visit(xml::Element* node) override {
     if (node->namespace_uri.empty()) {
       bool get_name = false;
       if (node->name == "manifest") {
@@ -205,18 +198,15 @@ class ManifestVisitor : public BaseVisitor {
         }
       } else if (node->name == "application") {
         get_name = true;
-        xml::Attribute* attr =
-            node->FindAttribute(xml::kSchemaAndroid, "backupAgent");
+        xml::Attribute* attr = node->FindAttribute(xml::kSchemaAndroid, "backupAgent");
         if (attr) {
-          Maybe<std::string> result =
-              util::GetFullyQualifiedClassName(package_, attr->value);
+          Maybe<std::string> result = util::GetFullyQualifiedClassName(package_, attr->value);
           if (result) {
             AddClass(node->line_number, result.value());
           }
         }
         if (main_dex_only_) {
-          xml::Attribute* default_process =
-              node->FindAttribute(xml::kSchemaAndroid, "process");
+          xml::Attribute* default_process = node->FindAttribute(xml::kSchemaAndroid, "process");
           if (default_process) {
             default_process_ = default_process->value;
           }
@@ -226,8 +216,7 @@ class ManifestVisitor : public BaseVisitor {
         get_name = true;
 
         if (main_dex_only_) {
-          xml::Attribute* component_process =
-              node->FindAttribute(xml::kSchemaAndroid, "process");
+          xml::Attribute* component_process = node->FindAttribute(xml::kSchemaAndroid, "process");
 
           const std::string& process =
               component_process ? component_process->value : default_process_;
@@ -242,8 +231,7 @@ class ManifestVisitor : public BaseVisitor {
         get_name = attr != nullptr;
 
         if (get_name) {
-          Maybe<std::string> result =
-              util::GetFullyQualifiedClassName(package_, attr->value);
+          Maybe<std::string> result = util::GetFullyQualifiedClassName(package_, attr->value);
           if (result) {
             AddClass(node->line_number, result.value());
           }
@@ -261,8 +249,7 @@ class ManifestVisitor : public BaseVisitor {
   std::string default_process_;
 };
 
-bool CollectProguardRulesForManifest(const Source& source,
-                                     xml::XmlResource* res, KeepSet* keep_set,
+bool CollectProguardRulesForManifest(const Source& source, xml::XmlResource* res, KeepSet* keep_set,
                                      bool main_dex_only) {
   ManifestVisitor visitor(source, keep_set, main_dex_only);
   if (res->root) {
@@ -272,8 +259,7 @@ bool CollectProguardRulesForManifest(const Source& source,
   return false;
 }
 
-bool CollectProguardRules(const Source& source, xml::XmlResource* res,
-                          KeepSet* keep_set) {
+bool CollectProguardRules(const Source& source, xml::XmlResource* res, KeepSet* keep_set) {
   if (!res->root) {
     return false;
   }
@@ -321,8 +307,7 @@ bool WriteKeepSet(std::ostream* out, const KeepSet& keep_set) {
     for (const Source& source : entry.second) {
       *out << "# Referenced at " << source << "\n";
     }
-    *out << "-keepclassmembers class * { *** " << entry.first << "(...); }\n"
-         << std::endl;
+    *out << "-keepclassmembers class * { *** " << entry.first << "(...); }\n" << std::endl;
   }
   return true;
 }
diff --git a/tools/aapt2/link/ManifestFixer_test.cpp b/tools/aapt2/link/ManifestFixer_test.cpp
index 80edb352f42c2..da7f410b8b086 100644
--- a/tools/aapt2/link/ManifestFixer_test.cpp
+++ b/tools/aapt2/link/ManifestFixer_test.cpp
@@ -122,7 +122,7 @@ TEST_F(ManifestFixerTest, UseDefaultSdkVersionsIfNonePresent) {
   xml::Element* el;
   xml::Attribute* attr;
 
-  el = xml::FindRootElement(doc.get());
+  el = doc->root.get();
   ASSERT_NE(nullptr, el);
   el = el->FindChild({}, "uses-sdk");
   ASSERT_NE(nullptr, el);
@@ -141,7 +141,7 @@ TEST_F(ManifestFixerTest, UseDefaultSdkVersionsIfNonePresent) {
                           options);
   ASSERT_NE(nullptr, doc);
 
-  el = xml::FindRootElement(doc.get());
+  el = doc->root.get();
   ASSERT_NE(nullptr, el);
   el = el->FindChild({}, "uses-sdk");
   ASSERT_NE(nullptr, el);
@@ -160,7 +160,7 @@ TEST_F(ManifestFixerTest, UseDefaultSdkVersionsIfNonePresent) {
                           options);
   ASSERT_NE(nullptr, doc);
 
-  el = xml::FindRootElement(doc.get());
+  el = doc->root.get();
   ASSERT_NE(nullptr, el);
   el = el->FindChild({}, "uses-sdk");
   ASSERT_NE(nullptr, el);
@@ -177,7 +177,7 @@ TEST_F(ManifestFixerTest, UseDefaultSdkVersionsIfNonePresent) {
                           options);
   ASSERT_NE(nullptr, doc);
 
-  el = xml::FindRootElement(doc.get());
+  el = doc->root.get();
   ASSERT_NE(nullptr, el);
   el = el->FindChild({}, "uses-sdk");
   ASSERT_NE(nullptr, el);
@@ -199,7 +199,7 @@ TEST_F(ManifestFixerTest, UsesSdkMustComeBeforeApplication) {
                                                             options);
   ASSERT_NE(nullptr, doc);
 
-  xml::Element* manifest_el = xml::FindRootElement(doc.get());
+  xml::Element* manifest_el = doc->root.get();
   ASSERT_NE(nullptr, manifest_el);
   ASSERT_EQ("manifest", manifest_el->name);
 
@@ -248,7 +248,7 @@ TEST_F(ManifestFixerTest, RenameManifestPackageAndFullyQualifyClasses) {
                                                             options);
   ASSERT_NE(nullptr, doc);
 
-  xml::Element* manifestEl = xml::FindRootElement(doc.get());
+  xml::Element* manifestEl = doc->root.get();
   ASSERT_NE(nullptr, manifestEl);
 
   xml::Attribute* attr = nullptr;
@@ -297,7 +297,7 @@ TEST_F(ManifestFixerTest,
                                                             options);
   ASSERT_NE(nullptr, doc);
 
-  xml::Element* manifest_el = xml::FindRootElement(doc.get());
+  xml::Element* manifest_el = doc->root.get();
   ASSERT_NE(nullptr, manifest_el);
 
   xml::Element* instrumentation_el =
@@ -321,7 +321,7 @@ TEST_F(ManifestFixerTest, UseDefaultVersionNameAndCode) {
                                                             options);
   ASSERT_NE(nullptr, doc);
 
-  xml::Element* manifest_el = xml::FindRootElement(doc.get());
+  xml::Element* manifest_el = doc->root.get();
   ASSERT_NE(nullptr, manifest_el);
 
   xml::Attribute* attr =
@@ -344,7 +344,7 @@ TEST_F(ManifestFixerTest, EnsureManifestAttributesAreTyped) {
       Verify("<manifest package=\"android\" coreApp=\"true\" />");
   ASSERT_NE(nullptr, doc);
 
-  xml::Element* el = xml::FindRootElement(doc.get());
+  xml::Element* el = doc->root.get();
   ASSERT_NE(nullptr, el);
 
   EXPECT_EQ("manifest", el->name);
diff --git a/tools/aapt2/link/XmlCompatVersioner.cpp b/tools/aapt2/link/XmlCompatVersioner.cpp
index f1f4e3b7f05ff..20ebdc696814d 100644
--- a/tools/aapt2/link/XmlCompatVersioner.cpp
+++ b/tools/aapt2/link/XmlCompatVersioner.cpp
@@ -107,7 +107,7 @@ std::unique_ptr<xml::XmlResource> XmlCompatVersioner::ProcessDoc(
   std::unique_ptr<xml::XmlResource> cloned_doc = util::make_unique<xml::XmlResource>(doc->file);
   cloned_doc->file.config.sdkVersion = static_cast<uint16_t>(target_api);
 
-  cloned_doc->root = doc->root->Clone([&](const xml::Element& el, xml::Element* out_el) {
+  cloned_doc->root = doc->root->CloneElement([&](const xml::Element& el, xml::Element* out_el) {
     for (const auto& attr : el.attributes) {
       if (!attr.compiled_attribute) {
         // Just copy if this isn't a compiled attribute.
diff --git a/tools/aapt2/link/XmlCompatVersioner_test.cpp b/tools/aapt2/link/XmlCompatVersioner_test.cpp
index ce6605c6ad97d..29ad25f79ab98 100644
--- a/tools/aapt2/link/XmlCompatVersioner_test.cpp
+++ b/tools/aapt2/link/XmlCompatVersioner_test.cpp
@@ -19,6 +19,12 @@
 #include "Linkers.h"
 #include "test/Test.h"
 
+using ::aapt::test::ValueEq;
+using ::testing::Eq;
+using ::testing::IsNull;
+using ::testing::NotNull;
+using ::testing::SizeIs;
+
 namespace aapt {
 
 constexpr auto TYPE_DIMENSION = android::ResTable_map::TYPE_DIMENSION;
@@ -68,12 +74,12 @@ class XmlCompatVersionerTest : public ::testing::Test {
 };
 
 TEST_F(XmlCompatVersionerTest, NoRulesOnlyStripsAndCopies) {
-  auto doc = test::BuildXmlDomForPackageName(context_.get(), R"EOF(
+  auto doc = test::BuildXmlDomForPackageName(context_.get(), R"(
       <View xmlns:android="http://schemas.android.com/apk/res/android"
           xmlns:app="http://schemas.android.com/apk/res-auto"
           android:paddingHorizontal="24dp"
           app:foo="16dp"
-          foo="bar"/>)EOF");
+          foo="bar"/>)");
 
   XmlReferenceLinker linker;
   ASSERT_TRUE(linker.Consume(context_.get(), doc.get()));
@@ -84,35 +90,35 @@ TEST_F(XmlCompatVersionerTest, NoRulesOnlyStripsAndCopies) {
   XmlCompatVersioner versioner(&rules);
   std::vector<std::unique_ptr<xml::XmlResource>> versioned_docs =
       versioner.Process(context_.get(), doc.get(), api_range);
-  ASSERT_EQ(2u, versioned_docs.size());
+  ASSERT_THAT(versioned_docs, SizeIs(2u));
 
   xml::Element* el;
 
   // Source XML file's sdkVersion == 0, so the first one must also have the same sdkVersion.
-  EXPECT_EQ(static_cast<uint16_t>(0), versioned_docs[0]->file.config.sdkVersion);
-  el = xml::FindRootElement(versioned_docs[0].get());
-  ASSERT_NE(nullptr, el);
-  EXPECT_EQ(2u, el->attributes.size());
-  EXPECT_EQ(nullptr, el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal"));
-  EXPECT_NE(nullptr, el->FindAttribute(xml::kSchemaAuto, "foo"));
-  EXPECT_NE(nullptr, el->FindAttribute({}, "foo"));
+  EXPECT_THAT(versioned_docs[0]->file.config.sdkVersion, Eq(0u));
+  el = versioned_docs[0]->root.get();
+  ASSERT_THAT(el, NotNull());
+  EXPECT_THAT(el->attributes, SizeIs(2u));
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal"), IsNull());
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAuto, "foo"), NotNull());
+  EXPECT_THAT(el->FindAttribute({}, "foo"), NotNull());
 
-  EXPECT_EQ(static_cast<uint16_t>(SDK_LOLLIPOP_MR1), versioned_docs[1]->file.config.sdkVersion);
-  el = xml::FindRootElement(versioned_docs[1].get());
-  ASSERT_NE(nullptr, el);
-  EXPECT_EQ(3u, el->attributes.size());
-  EXPECT_NE(nullptr, el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal"));
-  EXPECT_NE(nullptr, el->FindAttribute(xml::kSchemaAuto, "foo"));
-  EXPECT_NE(nullptr, el->FindAttribute({}, "foo"));
+  EXPECT_THAT(versioned_docs[1]->file.config.sdkVersion, Eq(SDK_LOLLIPOP_MR1));
+  el = versioned_docs[1]->root.get();
+  ASSERT_THAT(el, NotNull());
+  EXPECT_THAT(el->attributes, SizeIs(3u));
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal"), NotNull());
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAuto, "foo"), NotNull());
+  EXPECT_THAT(el->FindAttribute({}, "foo"), NotNull());
 }
 
 TEST_F(XmlCompatVersionerTest, SingleRule) {
-  auto doc = test::BuildXmlDomForPackageName(context_.get(), R"EOF(
+  auto doc = test::BuildXmlDomForPackageName(context_.get(), R"(
       <View xmlns:android="http://schemas.android.com/apk/res/android"
           xmlns:app="http://schemas.android.com/apk/res-auto"
           android:paddingHorizontal="24dp"
           app:foo="16dp"
-          foo="bar"/>)EOF");
+          foo="bar"/>)");
 
   XmlReferenceLinker linker;
   ASSERT_TRUE(linker.Consume(context_.get(), doc.get()));
@@ -129,51 +135,51 @@ TEST_F(XmlCompatVersionerTest, SingleRule) {
   XmlCompatVersioner versioner(&rules);
   std::vector<std::unique_ptr<xml::XmlResource>> versioned_docs =
       versioner.Process(context_.get(), doc.get(), api_range);
-  ASSERT_EQ(2u, versioned_docs.size());
+  ASSERT_THAT(versioned_docs, SizeIs(2u));
 
   xml::Element* el;
 
-  EXPECT_EQ(static_cast<uint16_t>(0), versioned_docs[0]->file.config.sdkVersion);
-  el = xml::FindRootElement(versioned_docs[0].get());
-  ASSERT_NE(nullptr, el);
-  EXPECT_EQ(4u, el->attributes.size());
-  EXPECT_EQ(nullptr, el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal"));
-  EXPECT_NE(nullptr, el->FindAttribute(xml::kSchemaAuto, "foo"));
-  EXPECT_NE(nullptr, el->FindAttribute({}, "foo"));
+  EXPECT_THAT(versioned_docs[0]->file.config.sdkVersion, Eq(0u));
+  el = versioned_docs[0]->root.get();
+  ASSERT_THAT(el, NotNull());
+  EXPECT_THAT(el->attributes, SizeIs(4u));
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal"), IsNull());
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAuto, "foo"), NotNull());
+  EXPECT_THAT(el->FindAttribute({}, "foo"), NotNull());
 
   xml::Attribute* attr = el->FindAttribute(xml::kSchemaAndroid, "paddingLeft");
-  ASSERT_NE(nullptr, attr);
-  ASSERT_NE(nullptr, attr->compiled_value);
+  ASSERT_THAT(attr, NotNull());
+  ASSERT_THAT(attr->compiled_value, NotNull());
   ASSERT_TRUE(attr->compiled_attribute);
 
   attr = el->FindAttribute(xml::kSchemaAndroid, "paddingRight");
-  ASSERT_NE(nullptr, attr);
-  ASSERT_NE(nullptr, attr->compiled_value);
+  ASSERT_THAT(attr, NotNull());
+  ASSERT_THAT(attr->compiled_value, NotNull());
   ASSERT_TRUE(attr->compiled_attribute);
 
-  EXPECT_EQ(static_cast<uint16_t>(SDK_LOLLIPOP_MR1), versioned_docs[1]->file.config.sdkVersion);
-  el = xml::FindRootElement(versioned_docs[1].get());
-  ASSERT_NE(nullptr, el);
-  EXPECT_EQ(5u, el->attributes.size());
-  EXPECT_NE(nullptr, el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal"));
-  EXPECT_NE(nullptr, el->FindAttribute(xml::kSchemaAuto, "foo"));
-  EXPECT_NE(nullptr, el->FindAttribute({}, "foo"));
+  EXPECT_THAT(versioned_docs[1]->file.config.sdkVersion, Eq(SDK_LOLLIPOP_MR1));
+  el = versioned_docs[1]->root.get();
+  ASSERT_THAT(el, NotNull());
+  EXPECT_THAT(el->attributes, SizeIs(5u));
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal"), NotNull());
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAuto, "foo"), NotNull());
+  EXPECT_THAT(el->FindAttribute({}, "foo"), NotNull());
 
   attr = el->FindAttribute(xml::kSchemaAndroid, "paddingLeft");
-  ASSERT_NE(nullptr, attr);
-  ASSERT_NE(nullptr, attr->compiled_value);
+  ASSERT_THAT(attr, NotNull());
+  ASSERT_THAT(attr->compiled_value, NotNull());
   ASSERT_TRUE(attr->compiled_attribute);
 
   attr = el->FindAttribute(xml::kSchemaAndroid, "paddingRight");
-  ASSERT_NE(nullptr, attr);
-  ASSERT_NE(nullptr, attr->compiled_value);
+  ASSERT_THAT(attr, NotNull());
+  ASSERT_THAT(attr->compiled_value, NotNull());
   ASSERT_TRUE(attr->compiled_attribute);
 }
 
 TEST_F(XmlCompatVersionerTest, ChainedRule) {
-  auto doc = test::BuildXmlDomForPackageName(context_.get(), R"EOF(
+  auto doc = test::BuildXmlDomForPackageName(context_.get(), R"(
       <View xmlns:android="http://schemas.android.com/apk/res/android"
-          android:paddingHorizontal="24dp" />)EOF");
+          android:paddingHorizontal="24dp" />)");
 
   XmlReferenceLinker linker;
   ASSERT_TRUE(linker.Consume(context_.get(), doc.get()));
@@ -193,71 +199,70 @@ TEST_F(XmlCompatVersionerTest, ChainedRule) {
   XmlCompatVersioner versioner(&rules);
   std::vector<std::unique_ptr<xml::XmlResource>> versioned_docs =
       versioner.Process(context_.get(), doc.get(), api_range);
-  ASSERT_EQ(3u, versioned_docs.size());
+  ASSERT_THAT(versioned_docs, SizeIs(3u));
 
   xml::Element* el;
 
-  EXPECT_EQ(static_cast<uint16_t>(0), versioned_docs[0]->file.config.sdkVersion);
-  el = xml::FindRootElement(versioned_docs[0].get());
-  ASSERT_NE(nullptr, el);
-  EXPECT_EQ(2u, el->attributes.size());
-  EXPECT_EQ(nullptr, el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal"));
+  EXPECT_THAT(versioned_docs[0]->file.config.sdkVersion, Eq(0u));
+  el = versioned_docs[0]->root.get();
+  ASSERT_THAT(el, NotNull());
+  EXPECT_THAT(el->attributes, SizeIs(2u));
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal"), IsNull());
 
   xml::Attribute* attr = el->FindAttribute(xml::kSchemaAndroid, "paddingLeft");
-  ASSERT_NE(nullptr, attr);
-  ASSERT_NE(nullptr, attr->compiled_value);
+  ASSERT_THAT(attr, NotNull());
+  ASSERT_THAT(attr->compiled_value, NotNull());
   ASSERT_TRUE(attr->compiled_attribute);
 
   attr = el->FindAttribute(xml::kSchemaAndroid, "paddingRight");
-  ASSERT_NE(nullptr, attr);
-  ASSERT_NE(nullptr, attr->compiled_value);
+  ASSERT_THAT(attr, NotNull());
+  ASSERT_THAT(attr->compiled_value, NotNull());
   ASSERT_TRUE(attr->compiled_attribute);
 
-  EXPECT_EQ(static_cast<uint16_t>(SDK_HONEYCOMB), versioned_docs[1]->file.config.sdkVersion);
-  el = xml::FindRootElement(versioned_docs[1].get());
-  ASSERT_NE(nullptr, el);
-  EXPECT_EQ(1u, el->attributes.size());
-  EXPECT_EQ(nullptr, el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal"));
-  EXPECT_EQ(nullptr, el->FindAttribute(xml::kSchemaAndroid, "paddingLeft"));
-  EXPECT_EQ(nullptr, el->FindAttribute(xml::kSchemaAndroid, "paddingRight"));
+  EXPECT_THAT(versioned_docs[1]->file.config.sdkVersion, Eq(SDK_HONEYCOMB));
+  el = versioned_docs[1]->root.get();
+  ASSERT_THAT(el, NotNull());
+  EXPECT_THAT(el->attributes, SizeIs(1u));
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal"), IsNull());
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAndroid, "paddingLeft"), IsNull());
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAndroid, "paddingRight"), IsNull());
 
   attr = el->FindAttribute(xml::kSchemaAndroid, "progressBarPadding");
-  ASSERT_NE(nullptr, attr);
-  ASSERT_NE(nullptr, attr->compiled_value);
+  ASSERT_THAT(attr, NotNull());
+  ASSERT_THAT(attr->compiled_value, NotNull());
   ASSERT_TRUE(attr->compiled_attribute);
 
-  EXPECT_EQ(static_cast<uint16_t>(SDK_LOLLIPOP_MR1), versioned_docs[2]->file.config.sdkVersion);
-  el = xml::FindRootElement(versioned_docs[2].get());
-  ASSERT_NE(nullptr, el);
-  EXPECT_EQ(2u, el->attributes.size());
-  EXPECT_EQ(nullptr, el->FindAttribute(xml::kSchemaAndroid, "paddingLeft"));
-  EXPECT_EQ(nullptr, el->FindAttribute(xml::kSchemaAndroid, "paddingRight"));
+  EXPECT_THAT(versioned_docs[2]->file.config.sdkVersion, Eq(SDK_LOLLIPOP_MR1));
+  el = versioned_docs[2]->root.get();
+  ASSERT_THAT(el, NotNull());
+  EXPECT_THAT(el->attributes, SizeIs(2u));
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAndroid, "paddingLeft"), IsNull());
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAndroid, "paddingRight"), IsNull());
 
   attr = el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal");
-  ASSERT_NE(nullptr, attr);
-  ASSERT_NE(nullptr, attr->compiled_value);
+  ASSERT_THAT(attr, NotNull());
+  ASSERT_THAT(attr->compiled_value, NotNull());
   ASSERT_TRUE(attr->compiled_attribute);
 
   attr = el->FindAttribute(xml::kSchemaAndroid, "progressBarPadding");
-  ASSERT_NE(nullptr, attr);
-  ASSERT_NE(nullptr, attr->compiled_value);
+  ASSERT_THAT(attr, NotNull());
+  ASSERT_THAT(attr->compiled_value, NotNull());
   ASSERT_TRUE(attr->compiled_attribute);
 }
 
 TEST_F(XmlCompatVersionerTest, DegradeRuleOverridesExistingAttribute) {
-  auto doc = test::BuildXmlDomForPackageName(context_.get(), R"EOF(
+  auto doc = test::BuildXmlDomForPackageName(context_.get(), R"(
       <View xmlns:android="http://schemas.android.com/apk/res/android"
           android:paddingHorizontal="24dp"
           android:paddingLeft="16dp"
-          android:paddingRight="16dp"/>)EOF");
+          android:paddingRight="16dp"/>)");
 
   XmlReferenceLinker linker;
   ASSERT_TRUE(linker.Consume(context_.get(), doc.get()));
 
-  Item* padding_horizontal_value = xml::FindRootElement(doc.get())
-                                       ->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal")
-                                       ->compiled_value.get();
-  ASSERT_NE(nullptr, padding_horizontal_value);
+  Item* padding_horizontal_value =
+      doc->root->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal")->compiled_value.get();
+  ASSERT_THAT(padding_horizontal_value, NotNull());
 
   XmlCompatVersioner::Rules rules;
   rules[R::attr::paddingHorizontal] =
@@ -271,50 +276,50 @@ TEST_F(XmlCompatVersionerTest, DegradeRuleOverridesExistingAttribute) {
   XmlCompatVersioner versioner(&rules);
   std::vector<std::unique_ptr<xml::XmlResource>> versioned_docs =
       versioner.Process(context_.get(), doc.get(), api_range);
-  ASSERT_EQ(2u, versioned_docs.size());
+  ASSERT_THAT(versioned_docs, SizeIs(2u));
 
   xml::Element* el;
 
-  EXPECT_EQ(static_cast<uint16_t>(0), versioned_docs[0]->file.config.sdkVersion);
-  el = xml::FindRootElement(versioned_docs[0].get());
-  ASSERT_NE(nullptr, el);
-  EXPECT_EQ(2u, el->attributes.size());
-  EXPECT_EQ(nullptr, el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal"));
+  EXPECT_THAT(versioned_docs[0]->file.config.sdkVersion, Eq(0u));
+  el = versioned_docs[0]->root.get();
+  ASSERT_THAT(el, NotNull());
+  EXPECT_THAT(el->attributes, SizeIs(2u));
+  EXPECT_THAT(el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal"), IsNull());
 
   xml::Attribute* attr = el->FindAttribute(xml::kSchemaAndroid, "paddingLeft");
-  ASSERT_NE(nullptr, attr);
-  ASSERT_NE(nullptr, attr->compiled_value);
-  ASSERT_TRUE(padding_horizontal_value->Equals(attr->compiled_value.get()));
+  ASSERT_THAT(attr, NotNull());
+  ASSERT_THAT(attr->compiled_value, NotNull());
   ASSERT_TRUE(attr->compiled_attribute);
+  ASSERT_THAT(*attr->compiled_value, ValueEq(padding_horizontal_value));
 
   attr = el->FindAttribute(xml::kSchemaAndroid, "paddingRight");
-  ASSERT_NE(nullptr, attr);
-  ASSERT_NE(nullptr, attr->compiled_value);
-  ASSERT_TRUE(padding_horizontal_value->Equals(attr->compiled_value.get()));
+  ASSERT_THAT(attr, NotNull());
+  ASSERT_THAT(attr->compiled_value, NotNull());
   ASSERT_TRUE(attr->compiled_attribute);
+  ASSERT_THAT(*attr->compiled_value, ValueEq(padding_horizontal_value));
 
-  EXPECT_EQ(static_cast<uint16_t>(SDK_LOLLIPOP_MR1), versioned_docs[1]->file.config.sdkVersion);
-  el = xml::FindRootElement(versioned_docs[1].get());
-  ASSERT_NE(nullptr, el);
-  EXPECT_EQ(3u, el->attributes.size());
+  EXPECT_THAT(versioned_docs[1]->file.config.sdkVersion, Eq(SDK_LOLLIPOP_MR1));
+  el = versioned_docs[1]->root.get();
+  ASSERT_THAT(el, NotNull());
+  EXPECT_THAT(el->attributes, SizeIs(3u));
 
   attr = el->FindAttribute(xml::kSchemaAndroid, "paddingHorizontal");
-  ASSERT_NE(nullptr, attr);
-  ASSERT_NE(nullptr, attr->compiled_value);
-  ASSERT_TRUE(padding_horizontal_value->Equals(attr->compiled_value.get()));
+  ASSERT_THAT(attr, NotNull());
+  ASSERT_THAT(attr->compiled_value, NotNull());
   ASSERT_TRUE(attr->compiled_attribute);
+  ASSERT_THAT(*attr->compiled_value, ValueEq(padding_horizontal_value));
 
   attr = el->FindAttribute(xml::kSchemaAndroid, "paddingLeft");
-  ASSERT_NE(nullptr, attr);
-  ASSERT_NE(nullptr, attr->compiled_value);
-  ASSERT_TRUE(padding_horizontal_value->Equals(attr->compiled_value.get()));
+  ASSERT_THAT(attr, NotNull());
+  ASSERT_THAT(attr->compiled_value, NotNull());
   ASSERT_TRUE(attr->compiled_attribute);
+  ASSERT_THAT(*attr->compiled_value, ValueEq(padding_horizontal_value));
 
   attr = el->FindAttribute(xml::kSchemaAndroid, "paddingRight");
-  ASSERT_NE(nullptr, attr);
-  ASSERT_NE(nullptr, attr->compiled_value);
-  ASSERT_TRUE(padding_horizontal_value->Equals(attr->compiled_value.get()));
+  ASSERT_THAT(attr, NotNull());
+  ASSERT_THAT(attr->compiled_value, NotNull());
   ASSERT_TRUE(attr->compiled_attribute);
+  ASSERT_THAT(*attr->compiled_value, ValueEq(padding_horizontal_value));
 }
 
 }  // namespace aapt
diff --git a/tools/aapt2/link/XmlNamespaceRemover.cpp b/tools/aapt2/link/XmlNamespaceRemover.cpp
index 24aa5660ae309..b5e2423d58dc1 100644
--- a/tools/aapt2/link/XmlNamespaceRemover.cpp
+++ b/tools/aapt2/link/XmlNamespaceRemover.cpp
@@ -24,37 +24,19 @@ namespace aapt {
 
 namespace {
 
-/**
- * Visits each xml Node, removing URI references and nested namespaces.
- */
+// Visits each xml Node, removing URI references and nested namespaces.
 class XmlVisitor : public xml::Visitor {
  public:
   explicit XmlVisitor(bool keep_uris) : keep_uris_(keep_uris) {}
 
   void Visit(xml::Element* el) override {
-    // Strip namespaces
-    for (auto& child : el->children) {
-      while (child && xml::NodeCast<xml::Namespace>(child.get())) {
-        if (child->children.empty()) {
-          child = {};
-        } else {
-          child = std::move(child->children.front());
-          child->parent = el;
-        }
-      }
-    }
-    el->children.erase(
-        std::remove_if(el->children.begin(), el->children.end(),
-                       [](const std::unique_ptr<xml::Node>& child) -> bool {
-                         return child == nullptr;
-                       }),
-        el->children.end());
+    el->namespace_decls.clear();
 
     if (!keep_uris_) {
       for (xml::Attribute& attr : el->attributes) {
-        attr.namespace_uri = std::string();
+        attr.namespace_uri.clear();
       }
-      el->namespace_uri = std::string();
+      el->namespace_uri.clear();
     }
     xml::Visitor::Visit(el);
   }
@@ -67,19 +49,11 @@ class XmlVisitor : public xml::Visitor {
 
 }  // namespace
 
-bool XmlNamespaceRemover::Consume(IAaptContext* context,
-                                  xml::XmlResource* resource) {
+bool XmlNamespaceRemover::Consume(IAaptContext* context, xml::XmlResource* resource) {
   if (!resource->root) {
     return false;
   }
-  // Replace any root namespaces until the root is a non-namespace node
-  while (xml::NodeCast<xml::Namespace>(resource->root.get())) {
-    if (resource->root->children.empty()) {
-      break;
-    }
-    resource->root = std::move(resource->root->children.front());
-    resource->root->parent = nullptr;
-  }
+
   XmlVisitor visitor(keep_uris_);
   resource->root->Accept(&visitor);
   return true;
diff --git a/tools/aapt2/link/XmlNamespaceRemover_test.cpp b/tools/aapt2/link/XmlNamespaceRemover_test.cpp
index a176c03a64325..df4920fde37f2 100644
--- a/tools/aapt2/link/XmlNamespaceRemover_test.cpp
+++ b/tools/aapt2/link/XmlNamespaceRemover_test.cpp
@@ -18,6 +18,10 @@
 
 #include "test/Test.h"
 
+using ::testing::NotNull;
+using ::testing::SizeIs;
+using ::testing::StrEq;
+
 namespace aapt {
 
 class XmlUriTestVisitor : public xml::Visitor {
@@ -25,16 +29,14 @@ class XmlUriTestVisitor : public xml::Visitor {
   XmlUriTestVisitor() = default;
 
   void Visit(xml::Element* el) override {
-    for (const auto& attr : el->attributes) {
-      EXPECT_EQ(std::string(), attr.namespace_uri);
-    }
-    EXPECT_EQ(std::string(), el->namespace_uri);
-    xml::Visitor::Visit(el);
-  }
+    EXPECT_THAT(el->namespace_decls, SizeIs(0u));
 
-  void Visit(xml::Namespace* ns) override {
-    EXPECT_EQ(std::string(), ns->namespace_uri);
-    xml::Visitor::Visit(ns);
+    for (const auto& attr : el->attributes) {
+      EXPECT_THAT(attr.namespace_uri, StrEq(""));
+    }
+    EXPECT_THAT(el->namespace_uri, StrEq(""));
+
+    xml::Visitor::Visit(el);
   }
 
  private:
@@ -45,10 +47,9 @@ class XmlNamespaceTestVisitor : public xml::Visitor {
  public:
   XmlNamespaceTestVisitor() = default;
 
-  void Visit(xml::Namespace* ns) override {
-    ADD_FAILURE() << "Detected namespace: " << ns->namespace_prefix << "=\""
-                  << ns->namespace_uri << "\"";
-    xml::Visitor::Visit(ns);
+  void Visit(xml::Element* el) override {
+    EXPECT_THAT(el->namespace_decls, SizeIs(0u));
+    xml::Visitor::Visit(el);
   }
 
  private:
@@ -58,8 +59,7 @@ class XmlNamespaceTestVisitor : public xml::Visitor {
 class XmlNamespaceRemoverTest : public ::testing::Test {
  public:
   void SetUp() override {
-    context_ =
-        test::ContextBuilder().SetCompilationPackage("com.app.test").Build();
+    context_ = test::ContextBuilder().SetCompilationPackage("com.app.test").Build();
   }
 
  protected:
@@ -75,8 +75,8 @@ TEST_F(XmlNamespaceRemoverTest, RemoveUris) {
   XmlNamespaceRemover remover;
   ASSERT_TRUE(remover.Consume(context_.get(), doc.get()));
 
-  xml::Node* root = doc.get()->root.get();
-  ASSERT_NE(root, nullptr);
+  xml::Node* root = doc->root.get();
+  ASSERT_THAT(root, NotNull());
 
   XmlUriTestVisitor visitor;
   root->Accept(&visitor);
@@ -93,8 +93,8 @@ TEST_F(XmlNamespaceRemoverTest, RemoveNamespaces) {
   XmlNamespaceRemover remover;
   ASSERT_TRUE(remover.Consume(context_.get(), doc.get()));
 
-  xml::Node* root = doc.get()->root.get();
-  ASSERT_NE(root, nullptr);
+  xml::Node* root = doc->root.get();
+  ASSERT_THAT(root, NotNull());
 
   XmlNamespaceTestVisitor visitor;
   root->Accept(&visitor);
@@ -112,8 +112,8 @@ TEST_F(XmlNamespaceRemoverTest, RemoveNestedNamespaces) {
   XmlNamespaceRemover remover;
   ASSERT_TRUE(remover.Consume(context_.get(), doc.get()));
 
-  xml::Node* root = doc.get()->root.get();
-  ASSERT_NE(root, nullptr);
+  xml::Node* root = doc->root.get();
+  ASSERT_THAT(root, NotNull());
 
   XmlNamespaceTestVisitor visitor;
   root->Accept(&visitor);
diff --git a/tools/aapt2/link/XmlReferenceLinker.cpp b/tools/aapt2/link/XmlReferenceLinker.cpp
index 721fc26399bcc..bcecd20038468 100644
--- a/tools/aapt2/link/XmlReferenceLinker.cpp
+++ b/tools/aapt2/link/XmlReferenceLinker.cpp
@@ -144,7 +144,9 @@ class XmlVisitor : public xml::PackageAwareVisitor {
     xml::PackageAwareVisitor::Visit(el);
   }
 
-  bool HasError() { return error_ || reference_visitor_.HasError(); }
+  bool HasError() {
+    return error_ || reference_visitor_.HasError();
+  }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(XmlVisitor);
diff --git a/tools/aapt2/link/XmlReferenceLinker_test.cpp b/tools/aapt2/link/XmlReferenceLinker_test.cpp
index 228cfb9e3d663..ef99355e5b5fb 100644
--- a/tools/aapt2/link/XmlReferenceLinker_test.cpp
+++ b/tools/aapt2/link/XmlReferenceLinker_test.cpp
@@ -79,20 +79,20 @@ class XmlReferenceLinkerTest : public ::testing::Test {
 };
 
 TEST_F(XmlReferenceLinkerTest, LinkBasicAttributes) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"EOF(
-        <View xmlns:android="http://schemas.android.com/apk/res/android"
-              android:layout_width="match_parent"
-              android:background="@color/green"
-              android:text="hello"
-              android:attr="\?hello"
-              nonAaptAttr="1"
-              nonAaptAttrRef="@id/id"
-              class="hello" />)EOF");
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"(
+      <View xmlns:android="http://schemas.android.com/apk/res/android"
+            android:layout_width="match_parent"
+            android:background="@color/green"
+            android:text="hello"
+            android:attr="\?hello"
+            nonAaptAttr="1"
+            nonAaptAttrRef="@id/id"
+            class="hello" />)");
 
   XmlReferenceLinker linker;
   ASSERT_TRUE(linker.Consume(context_.get(), doc.get()));
 
-  xml::Element* view_el = xml::FindRootElement(doc.get());
+  xml::Element* view_el = doc->root.get();
   ASSERT_THAT(view_el, NotNull());
 
   xml::Attribute* xml_attr = view_el->FindAttribute(xml::kSchemaAndroid, "layout_width");
@@ -138,32 +138,32 @@ TEST_F(XmlReferenceLinkerTest, LinkBasicAttributes) {
 }
 
 TEST_F(XmlReferenceLinkerTest, PrivateSymbolsAreNotLinked) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"EOF(
-        <View xmlns:android="http://schemas.android.com/apk/res/android"
-              android:colorAccent="@android:color/hidden" />)EOF");
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"(
+      <View xmlns:android="http://schemas.android.com/apk/res/android"
+          android:colorAccent="@android:color/hidden" />)");
 
   XmlReferenceLinker linker;
   ASSERT_FALSE(linker.Consume(context_.get(), doc.get()));
 }
 
 TEST_F(XmlReferenceLinkerTest, PrivateSymbolsAreLinkedWhenReferenceHasStarPrefix) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"EOF(
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"(
     <View xmlns:android="http://schemas.android.com/apk/res/android"
-          android:colorAccent="@*android:color/hidden" />)EOF");
+          android:colorAccent="@*android:color/hidden" />)");
 
   XmlReferenceLinker linker;
   ASSERT_TRUE(linker.Consume(context_.get(), doc.get()));
 }
 
 TEST_F(XmlReferenceLinkerTest, LinkMangledAttributes) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"EOF(
-            <View xmlns:support="http://schemas.android.com/apk/res/com.android.support"
-                  support:colorAccent="#ff0000" />)EOF");
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"(
+      <View xmlns:support="http://schemas.android.com/apk/res/com.android.support"
+          support:colorAccent="#ff0000" />)");
 
   XmlReferenceLinker linker;
   ASSERT_TRUE(linker.Consume(context_.get(), doc.get()));
 
-  xml::Element* view_el = xml::FindRootElement(doc.get());
+  xml::Element* view_el = doc->root.get();
   ASSERT_THAT(view_el, NotNull());
 
   xml::Attribute* xml_attr =
@@ -175,14 +175,14 @@ TEST_F(XmlReferenceLinkerTest, LinkMangledAttributes) {
 }
 
 TEST_F(XmlReferenceLinkerTest, LinkAutoResReference) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"EOF(
-            <View xmlns:app="http://schemas.android.com/apk/res-auto"
-                  app:colorAccent="@app:color/red" />)EOF");
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"(
+      <View xmlns:app="http://schemas.android.com/apk/res-auto"
+          app:colorAccent="@app:color/red" />)");
 
   XmlReferenceLinker linker;
   ASSERT_TRUE(linker.Consume(context_.get(), doc.get()));
 
-  xml::Element* view_el = xml::FindRootElement(doc.get());
+  xml::Element* view_el = doc->root.get();
   ASSERT_THAT(view_el, NotNull());
 
   xml::Attribute* xml_attr = view_el->FindAttribute(xml::kSchemaAuto, "colorAccent");
@@ -196,17 +196,15 @@ TEST_F(XmlReferenceLinkerTest, LinkAutoResReference) {
 }
 
 TEST_F(XmlReferenceLinkerTest, LinkViewWithShadowedPackageAlias) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"EOF(
-            <View xmlns:app="http://schemas.android.com/apk/res/android"
-                  app:attr="@app:id/id">
-              <View xmlns:app="http://schemas.android.com/apk/res/com.app.test"
-                    app:attr="@app:id/id"/>
-            </View>)EOF");
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"(
+      <View xmlns:app="http://schemas.android.com/apk/res/android" app:attr="@app:id/id">
+        <View xmlns:app="http://schemas.android.com/apk/res/com.app.test" app:attr="@app:id/id"/>
+      </View>)");
 
   XmlReferenceLinker linker;
   ASSERT_TRUE(linker.Consume(context_.get(), doc.get()));
 
-  xml::Element* view_el = xml::FindRootElement(doc.get());
+  xml::Element* view_el = doc->root.get();
   ASSERT_THAT(view_el, NotNull());
 
   // All attributes and references in this element should be referring to
@@ -235,14 +233,14 @@ TEST_F(XmlReferenceLinkerTest, LinkViewWithShadowedPackageAlias) {
 }
 
 TEST_F(XmlReferenceLinkerTest, LinkViewWithLocalPackageAndAliasOfTheSameName) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"EOF(
-            <View xmlns:android="http://schemas.android.com/apk/res/com.app.test"
-                  android:attr="@id/id"/>)EOF");
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"(
+      <View xmlns:android="http://schemas.android.com/apk/res/com.app.test"
+          android:attr="@id/id"/>)");
 
   XmlReferenceLinker linker;
   ASSERT_TRUE(linker.Consume(context_.get(), doc.get()));
 
-  xml::Element* view_el = xml::FindRootElement(doc.get());
+  xml::Element* view_el = doc->root.get();
   ASSERT_THAT(view_el, NotNull());
 
   // All attributes and references in this element should be referring to
diff --git a/tools/aapt2/proto/ProtoHelpers.cpp b/tools/aapt2/proto/ProtoHelpers.cpp
index 6b21364b5eb27..aa99c982f6aec 100644
--- a/tools/aapt2/proto/ProtoHelpers.cpp
+++ b/tools/aapt2/proto/ProtoHelpers.cpp
@@ -36,7 +36,7 @@ void SerializeSourceToPb(const Source& source, StringPool* src_pool, pb::Source*
   StringPool::Ref ref = src_pool->MakeRef(source.path);
   out_pb_source->set_path_idx(static_cast<uint32_t>(ref.index()));
   if (source.line) {
-    out_pb_source->set_line_no(static_cast<uint32_t>(source.line.value()));
+    out_pb_source->mutable_position()->set_line_number(static_cast<uint32_t>(source.line.value()));
   }
 }
 
@@ -46,29 +46,28 @@ void DeserializeSourceFromPb(const pb::Source& pb_source, const android::ResStri
     out_source->path = util::GetString(src_pool, pb_source.path_idx());
   }
 
-  if (pb_source.has_line_no()) {
-    out_source->line = static_cast<size_t>(pb_source.line_no());
+  if (pb_source.has_position()) {
+    out_source->line = static_cast<size_t>(pb_source.position().line_number());
   }
 }
 
 pb::SymbolStatus_Visibility SerializeVisibilityToPb(SymbolState state) {
   switch (state) {
     case SymbolState::kPrivate:
-      return pb::SymbolStatus_Visibility_Private;
+      return pb::SymbolStatus_Visibility_PRIVATE;
     case SymbolState::kPublic:
-      return pb::SymbolStatus_Visibility_Public;
+      return pb::SymbolStatus_Visibility_PUBLIC;
     default:
       break;
   }
-  return pb::SymbolStatus_Visibility_Unknown;
+  return pb::SymbolStatus_Visibility_UNKNOWN;
 }
 
-SymbolState DeserializeVisibilityFromPb(
-    pb::SymbolStatus_Visibility pb_visibility) {
+SymbolState DeserializeVisibilityFromPb(pb::SymbolStatus_Visibility pb_visibility) {
   switch (pb_visibility) {
-    case pb::SymbolStatus_Visibility_Private:
+    case pb::SymbolStatus_Visibility_PRIVATE:
       return SymbolState::kPrivate;
-    case pb::SymbolStatus_Visibility_Public:
+    case pb::SymbolStatus_Visibility_PUBLIC:
       return SymbolState::kPublic;
     default:
       break;
@@ -102,20 +101,20 @@ bool DeserializeConfigDescriptionFromPb(const pb::ConfigDescription& pb_config,
 pb::Reference_Type SerializeReferenceTypeToPb(Reference::Type type) {
   switch (type) {
     case Reference::Type::kResource:
-      return pb::Reference_Type_Ref;
+      return pb::Reference_Type_REFERENCE;
     case Reference::Type::kAttribute:
-      return pb::Reference_Type_Attr;
+      return pb::Reference_Type_ATTRIBUTE;
     default:
       break;
   }
-  return pb::Reference_Type_Ref;
+  return pb::Reference_Type_REFERENCE;
 }
 
 Reference::Type DeserializeReferenceTypeFromPb(pb::Reference_Type pb_type) {
   switch (pb_type) {
-    case pb::Reference_Type_Ref:
+    case pb::Reference_Type_REFERENCE:
       return Reference::Type::kResource;
-    case pb::Reference_Type_Attr:
+    case pb::Reference_Type_ATTRIBUTE:
       return Reference::Type::kAttribute;
     default:
       break;
@@ -126,32 +125,32 @@ Reference::Type DeserializeReferenceTypeFromPb(pb::Reference_Type pb_type) {
 pb::Plural_Arity SerializePluralEnumToPb(size_t plural_idx) {
   switch (plural_idx) {
     case Plural::Zero:
-      return pb::Plural_Arity_Zero;
+      return pb::Plural_Arity_ZERO;
     case Plural::One:
-      return pb::Plural_Arity_One;
+      return pb::Plural_Arity_ONE;
     case Plural::Two:
-      return pb::Plural_Arity_Two;
+      return pb::Plural_Arity_TWO;
     case Plural::Few:
-      return pb::Plural_Arity_Few;
+      return pb::Plural_Arity_FEW;
     case Plural::Many:
-      return pb::Plural_Arity_Many;
+      return pb::Plural_Arity_MANY;
     default:
       break;
   }
-  return pb::Plural_Arity_Other;
+  return pb::Plural_Arity_OTHER;
 }
 
 size_t DeserializePluralEnumFromPb(pb::Plural_Arity arity) {
   switch (arity) {
-    case pb::Plural_Arity_Zero:
+    case pb::Plural_Arity_ZERO:
       return Plural::Zero;
-    case pb::Plural_Arity_One:
+    case pb::Plural_Arity_ONE:
       return Plural::One;
-    case pb::Plural_Arity_Two:
+    case pb::Plural_Arity_TWO:
       return Plural::Two;
-    case pb::Plural_Arity_Few:
+    case pb::Plural_Arity_FEW:
       return Plural::Few;
-    case pb::Plural_Arity_Many:
+    case pb::Plural_Arity_MANY:
       return Plural::Many;
     default:
       break;
diff --git a/tools/aapt2/proto/ProtoHelpers.h b/tools/aapt2/proto/ProtoHelpers.h
index 344e9477ea714..2f268f44752c5 100644
--- a/tools/aapt2/proto/ProtoHelpers.h
+++ b/tools/aapt2/proto/ProtoHelpers.h
@@ -23,27 +23,23 @@
 #include "ResourceTable.h"
 #include "Source.h"
 #include "StringPool.h"
-#include "Format.pb.h"
+#include "Resources.pb.h"
+#include "ResourcesInternal.pb.h"
 
 namespace aapt {
 
-void SerializeStringPoolToPb(const StringPool& pool,
-                             pb::StringPool* out_pb_pool);
+void SerializeStringPoolToPb(const StringPool& pool, pb::StringPool* out_pb_pool);
 
-void SerializeSourceToPb(const Source& source, StringPool* src_pool,
-                         pb::Source* out_pb_source);
+void SerializeSourceToPb(const Source& source, StringPool* src_pool, pb::Source* out_pb_source);
 
-void DeserializeSourceFromPb(const pb::Source& pb_source,
-                             const android::ResStringPool& src_pool,
+void DeserializeSourceFromPb(const pb::Source& pb_source, const android::ResStringPool& src_pool,
                              Source* out_source);
 
 pb::SymbolStatus_Visibility SerializeVisibilityToPb(SymbolState state);
 
-SymbolState DeserializeVisibilityFromPb(
-    pb::SymbolStatus_Visibility pb_visibility);
+SymbolState DeserializeVisibilityFromPb(pb::SymbolStatus_Visibility pb_visibility);
 
-void SerializeConfig(const ConfigDescription& config,
-                     pb::ConfigDescription* out_pb_config);
+void SerializeConfig(const ConfigDescription& config, pb::ConfigDescription* out_pb_config);
 
 bool DeserializeConfigDescriptionFromPb(const pb::ConfigDescription& pb_config,
                                         ConfigDescription* out_config);
diff --git a/tools/aapt2/proto/ProtoSerialize.h b/tools/aapt2/proto/ProtoSerialize.h
index 39c50038d5994..8c46642e9090a 100644
--- a/tools/aapt2/proto/ProtoSerialize.h
+++ b/tools/aapt2/proto/ProtoSerialize.h
@@ -30,11 +30,10 @@ namespace aapt {
 
 class CompiledFileOutputStream {
  public:
-  explicit CompiledFileOutputStream(
-      google::protobuf::io::ZeroCopyOutputStream* out);
+  explicit CompiledFileOutputStream(google::protobuf::io::ZeroCopyOutputStream* out);
 
   void WriteLittleEndian32(uint32_t value);
-  void WriteCompiledFile(const pb::CompiledFile* compiledFile);
+  void WriteCompiledFile(const pb::internal::CompiledFile* compiledFile);
   void WriteData(const BigBuffer* buffer);
   void WriteData(const void* data, size_t len);
   bool HadError();
@@ -52,7 +51,7 @@ class CompiledFileInputStream {
   explicit CompiledFileInputStream(const void* data, size_t size);
 
   bool ReadLittleEndian32(uint32_t* outVal);
-  bool ReadCompiledFile(pb::CompiledFile* outVal);
+  bool ReadCompiledFile(pb::internal::CompiledFile* outVal);
   bool ReadDataMetaData(uint64_t* outOffset, uint64_t* outLen);
 
  private:
@@ -64,13 +63,12 @@ class CompiledFileInputStream {
 };
 
 std::unique_ptr<pb::ResourceTable> SerializeTableToPb(ResourceTable* table);
-std::unique_ptr<ResourceTable> DeserializeTableFromPb(
-    const pb::ResourceTable& pbTable, const Source& source, IDiagnostics* diag);
+std::unique_ptr<ResourceTable> DeserializeTableFromPb(const pb::ResourceTable& pbTable,
+                                                      const Source& source, IDiagnostics* diag);
 
-std::unique_ptr<pb::CompiledFile> SerializeCompiledFileToPb(
-    const ResourceFile& file);
+std::unique_ptr<pb::internal::CompiledFile> SerializeCompiledFileToPb(const ResourceFile& file);
 std::unique_ptr<ResourceFile> DeserializeCompiledFileFromPb(
-    const pb::CompiledFile& pbFile, const Source& source, IDiagnostics* diag);
+    const pb::internal::CompiledFile& pbFile, const Source& source, IDiagnostics* diag);
 
 }  // namespace aapt
 
diff --git a/tools/aapt2/proto/TableProtoDeserializer.cpp b/tools/aapt2/proto/TableProtoDeserializer.cpp
index 37d5ed0cf59d9..b9d5878f2f715 100644
--- a/tools/aapt2/proto/TableProtoDeserializer.cpp
+++ b/tools/aapt2/proto/TableProtoDeserializer.cpp
@@ -55,66 +55,61 @@ class ReferenceIdToNameVisitor : public ValueVisitor {
 
 class PackagePbDeserializer {
  public:
-  PackagePbDeserializer(const android::ResStringPool* valuePool,
-                        const android::ResStringPool* sourcePool,
-                        const android::ResStringPool* symbolPool,
-                        const Source& source, IDiagnostics* diag)
-      : value_pool_(valuePool),
-        source_pool_(sourcePool),
-        symbol_pool_(symbolPool),
-        source_(source),
-        diag_(diag) {}
+  PackagePbDeserializer(const android::ResStringPool* sourcePool, const Source& source,
+                        IDiagnostics* diag)
+      : source_pool_(sourcePool), source_(source), diag_(diag) {
+  }
 
  public:
-  bool DeserializeFromPb(const pb::Package& pbPackage, ResourceTable* table) {
+  bool DeserializeFromPb(const pb::Package& pb_package, ResourceTable* table) {
     Maybe<uint8_t> id;
-    if (pbPackage.has_package_id()) {
-      id = static_cast<uint8_t>(pbPackage.package_id());
+    if (pb_package.has_package_id()) {
+      id = static_cast<uint8_t>(pb_package.package_id());
     }
 
-    std::map<ResourceId, ResourceNameRef> idIndex;
+    std::map<ResourceId, ResourceNameRef> id_index;
 
-    ResourceTablePackage* pkg = table->CreatePackage(pbPackage.package_name(), id);
-    for (const pb::Type& pbType : pbPackage.types()) {
-      const ResourceType* resType = ParseResourceType(pbType.name());
-      if (!resType) {
-        diag_->Error(DiagMessage(source_) << "unknown type '" << pbType.name() << "'");
+    ResourceTablePackage* pkg = table->CreatePackage(pb_package.package_name(), id);
+    for (const pb::Type& pb_type : pb_package.type()) {
+      const ResourceType* res_type = ParseResourceType(pb_type.name());
+      if (res_type == nullptr) {
+        diag_->Error(DiagMessage(source_) << "unknown type '" << pb_type.name() << "'");
         return {};
       }
 
-      ResourceTableType* type = pkg->FindOrCreateType(*resType);
+      ResourceTableType* type = pkg->FindOrCreateType(*res_type);
 
-      for (const pb::Entry& pbEntry : pbType.entries()) {
-        ResourceEntry* entry = type->FindOrCreateEntry(pbEntry.name());
+      for (const pb::Entry& pb_entry : pb_type.entry()) {
+        ResourceEntry* entry = type->FindOrCreateEntry(pb_entry.name());
 
-        // Deserialize the symbol status (public/private with source and
-        // comments).
-        if (pbEntry.has_symbol_status()) {
-          const pb::SymbolStatus& pbStatus = pbEntry.symbol_status();
-          if (pbStatus.has_source()) {
-            DeserializeSourceFromPb(pbStatus.source(), *source_pool_, &entry->symbol_status.source);
+        // Deserialize the symbol status (public/private with source and comments).
+        if (pb_entry.has_symbol_status()) {
+          const pb::SymbolStatus& pb_status = pb_entry.symbol_status();
+          if (pb_status.has_source()) {
+            DeserializeSourceFromPb(pb_status.source(), *source_pool_,
+                                    &entry->symbol_status.source);
           }
 
-          if (pbStatus.has_comment()) {
-            entry->symbol_status.comment = pbStatus.comment();
+          if (pb_status.has_comment()) {
+            entry->symbol_status.comment = pb_status.comment();
           }
 
-          entry->symbol_status.allow_new = pbStatus.allow_new();
+          entry->symbol_status.allow_new = pb_status.allow_new();
 
-          SymbolState visibility = DeserializeVisibilityFromPb(pbStatus.visibility());
+          SymbolState visibility = DeserializeVisibilityFromPb(pb_status.visibility());
           entry->symbol_status.state = visibility;
 
           if (visibility == SymbolState::kPublic) {
             // This is a public symbol, we must encode the ID now if there is one.
-            if (pbEntry.has_id()) {
-              entry->id = static_cast<uint16_t>(pbEntry.id());
+            if (pb_entry.has_id()) {
+              entry->id = static_cast<uint16_t>(pb_entry.id());
             }
 
             if (type->symbol_status.state != SymbolState::kPublic) {
               // If the type has not been made public, do so now.
               type->symbol_status.state = SymbolState::kPublic;
-              if (pbType.has_id()) {
-                type->id = static_cast<uint8_t>(pbType.id());
+              if (pb_type.has_id()) {
+                type->id = static_cast<uint8_t>(pb_type.id());
               }
             }
           } else if (visibility == SymbolState::kPrivate) {
@@ -124,45 +119,44 @@ class PackagePbDeserializer {
           }
         }
 
-        ResourceId resId(pbPackage.package_id(), pbType.id(), pbEntry.id());
-        if (resId.is_valid()) {
-          idIndex[resId] = ResourceNameRef(pkg->name, type->type, entry->name);
+        ResourceId resid(pb_package.package_id(), pb_type.id(), pb_entry.id());
+        if (resid.is_valid()) {
+          id_index[resid] = ResourceNameRef(pkg->name, type->type, entry->name);
         }
 
-        for (const pb::ConfigValue& pbConfigValue : pbEntry.config_values()) {
-          const pb::ConfigDescription& pbConfig = pbConfigValue.config();
+        for (const pb::ConfigValue& pb_config_value : pb_entry.config_value()) {
+          const pb::ConfigDescription& pb_config = pb_config_value.config();
 
           ConfigDescription config;
-          if (!DeserializeConfigDescriptionFromPb(pbConfig, &config)) {
+          if (!DeserializeConfigDescriptionFromPb(pb_config, &config)) {
             diag_->Error(DiagMessage(source_) << "invalid configuration");
             return {};
           }
 
-          ResourceConfigValue* configValue = entry->FindOrCreateValue(config, pbConfig.product());
-          if (configValue->value) {
+          ResourceConfigValue* config_value = entry->FindOrCreateValue(config, pb_config.product());
+          if (config_value->value) {
             // Duplicate config.
             diag_->Error(DiagMessage(source_) << "duplicate configuration");
             return {};
           }
 
-          configValue->value =
-              DeserializeValueFromPb(pbConfigValue.value(), config, &table->string_pool);
-          if (!configValue->value) {
+          config_value->value =
+              DeserializeValueFromPb(pb_config_value.value(), config, &table->string_pool);
+          if (!config_value->value) {
             return {};
           }
         }
       }
     }
 
-    ReferenceIdToNameVisitor visitor(&idIndex);
+    ReferenceIdToNameVisitor visitor(&id_index);
     VisitAllValuesInPackage(pkg, &visitor);
     return true;
   }
 
  private:
   std::unique_ptr<Item> DeserializeItemFromPb(const pb::Item& pb_item,
-                                              const ConfigDescription& config,
-                                              StringPool* pool) {
+                                              const ConfigDescription& config, StringPool* pool) {
     if (pb_item.has_ref()) {
       const pb::Reference& pb_ref = pb_item.ref();
       std::unique_ptr<Reference> ref = util::make_unique<Reference>();
@@ -173,45 +167,32 @@ class PackagePbDeserializer {
 
     } else if (pb_item.has_prim()) {
       const pb::Primitive& pb_prim = pb_item.prim();
-      android::Res_value prim = {};
-      prim.dataType = static_cast<uint8_t>(pb_prim.type());
-      prim.data = pb_prim.data();
-      return util::make_unique<BinaryPrimitive>(prim);
+      return util::make_unique<BinaryPrimitive>(static_cast<uint8_t>(pb_prim.type()),
+                                                pb_prim.data());
 
     } else if (pb_item.has_id()) {
       return util::make_unique<Id>();
 
     } else if (pb_item.has_str()) {
-      const uint32_t idx = pb_item.str().idx();
-      const std::string str = util::GetString(*value_pool_, idx);
-
-      const android::ResStringPool_span* spans = value_pool_->styleAt(idx);
-      if (spans && spans->name.index != android::ResStringPool_span::END) {
-        StyleString style_str = {str};
-        while (spans->name.index != android::ResStringPool_span::END) {
-          style_str.spans.push_back(
-              Span{util::GetString(*value_pool_, spans->name.index),
-                   spans->firstChar, spans->lastChar});
-          spans++;
-        }
-        return util::make_unique<StyledString>(pool->MakeRef(
-            style_str, StringPool::Context(StringPool::Context::kNormalPriority, config)));
-      }
       return util::make_unique<String>(
-          pool->MakeRef(str, StringPool::Context(config)));
+          pool->MakeRef(pb_item.str().value(), StringPool::Context(config)));
 
     } else if (pb_item.has_raw_str()) {
-      const uint32_t idx = pb_item.raw_str().idx();
-      const std::string str = util::GetString(*value_pool_, idx);
       return util::make_unique<RawString>(
-          pool->MakeRef(str, StringPool::Context(config)));
+          pool->MakeRef(pb_item.raw_str().value(), StringPool::Context(config)));
+
+    } else if (pb_item.has_styled_str()) {
+      const pb::StyledString& pb_str = pb_item.styled_str();
+      StyleString style_str{pb_str.value()};
+      for (const pb::StyledString::Span& pb_span : pb_str.span()) {
+        style_str.spans.push_back(Span{pb_span.tag(), pb_span.first_char(), pb_span.last_char()});
+      }
+      return util::make_unique<StyledString>(pool->MakeRef(
+          style_str, StringPool::Context(StringPool::Context::kNormalPriority, config)));
 
     } else if (pb_item.has_file()) {
-      const uint32_t idx = pb_item.file().path_idx();
-      const std::string str = util::GetString(*value_pool_, idx);
       return util::make_unique<FileReference>(pool->MakeRef(
-          str,
-          StringPool::Context(StringPool::Context::kHighPriority, config)));
+          pb_item.file().path(), StringPool::Context(StringPool::Context::kHighPriority, config)));
 
     } else {
       diag_->Error(DiagMessage(source_) << "unknown item");
@@ -222,8 +203,6 @@ class PackagePbDeserializer {
   std::unique_ptr<Value> DeserializeValueFromPb(const pb::Value& pb_value,
                                                 const ConfigDescription& config,
                                                 StringPool* pool) {
-    const bool is_weak = pb_value.has_weak() ? pb_value.weak() : false;
-
     std::unique_ptr<Value> value;
     if (pb_value.has_item()) {
       value = DeserializeItemFromPb(pb_value.item(), config, pool);
@@ -235,11 +214,11 @@ class PackagePbDeserializer {
       const pb::CompoundValue& pb_compound_value = pb_value.compound_value();
       if (pb_compound_value.has_attr()) {
         const pb::Attribute& pb_attr = pb_compound_value.attr();
-        std::unique_ptr<Attribute> attr = util::make_unique<Attribute>(is_weak);
+        std::unique_ptr<Attribute> attr = util::make_unique<Attribute>();
         attr->type_mask = pb_attr.format_flags();
         attr->min_int = pb_attr.min_int();
         attr->max_int = pb_attr.max_int();
-        for (const pb::Attribute_Symbol& pb_symbol : pb_attr.symbols()) {
+        for (const pb::Attribute_Symbol& pb_symbol : pb_attr.symbol()) {
           Attribute::Symbol symbol;
           DeserializeItemCommon(pb_symbol, &symbol.symbol);
           if (!DeserializeReferenceFromPb(pb_symbol.name(), &symbol.symbol)) {
@@ -255,20 +234,18 @@ class PackagePbDeserializer {
         std::unique_ptr<Style> style = util::make_unique<Style>();
         if (pb_style.has_parent()) {
           style->parent = Reference();
-          if (!DeserializeReferenceFromPb(pb_style.parent(),
-                                          &style->parent.value())) {
+          if (!DeserializeReferenceFromPb(pb_style.parent(), &style->parent.value())) {
             return {};
           }
 
           if (pb_style.has_parent_source()) {
             Source parent_source;
-            DeserializeSourceFromPb(pb_style.parent_source(), *source_pool_,
-                                    &parent_source);
+            DeserializeSourceFromPb(pb_style.parent_source(), *source_pool_, &parent_source);
             style->parent.value().SetSource(std::move(parent_source));
           }
         }
 
-        for (const pb::Style_Entry& pb_entry : pb_style.entries()) {
+        for (const pb::Style_Entry& pb_entry : pb_style.entry()) {
           Style::Entry entry;
           DeserializeItemCommon(pb_entry, &entry.key);
           if (!DeserializeReferenceFromPb(pb_entry.key(), &entry.key)) {
@@ -288,7 +265,7 @@ class PackagePbDeserializer {
       } else if (pb_compound_value.has_styleable()) {
         const pb::Styleable& pb_styleable = pb_compound_value.styleable();
         std::unique_ptr<Styleable> styleable = util::make_unique<Styleable>();
-        for (const pb::Styleable_Entry& pb_entry : pb_styleable.entries()) {
+        for (const pb::Styleable_Entry& pb_entry : pb_styleable.entry()) {
           Reference attr_ref;
           DeserializeItemCommon(pb_entry, &attr_ref);
           DeserializeReferenceFromPb(pb_entry.attr(), &attr_ref);
@@ -299,25 +276,23 @@ class PackagePbDeserializer {
       } else if (pb_compound_value.has_array()) {
         const pb::Array& pb_array = pb_compound_value.array();
         std::unique_ptr<Array> array = util::make_unique<Array>();
-        for (const pb::Array_Entry& pb_entry : pb_array.entries()) {
-          std::unique_ptr<Item> item =
-              DeserializeItemFromPb(pb_entry.item(), config, pool);
+        for (const pb::Array_Element& pb_entry : pb_array.element()) {
+          std::unique_ptr<Item> item = DeserializeItemFromPb(pb_entry.item(), config, pool);
           if (!item) {
             return {};
           }
 
           DeserializeItemCommon(pb_entry, item.get());
-          array->items.push_back(std::move(item));
+          array->elements.push_back(std::move(item));
         }
         value = std::move(array);
 
       } else if (pb_compound_value.has_plural()) {
         const pb::Plural& pb_plural = pb_compound_value.plural();
         std::unique_ptr<Plural> plural = util::make_unique<Plural>();
-        for (const pb::Plural_Entry& pb_entry : pb_plural.entries()) {
+        for (const pb::Plural_Entry& pb_entry : pb_plural.entry()) {
           size_t pluralIdx = DeserializePluralEnumFromPb(pb_entry.arity());
-          plural->values[pluralIdx] =
-              DeserializeItemFromPb(pb_entry.item(), config, pool);
+          plural->values[pluralIdx] = DeserializeItemFromPb(pb_entry.item(), config, pool);
           if (!plural->values[pluralIdx]) {
             return {};
           }
@@ -337,7 +312,7 @@ class PackagePbDeserializer {
 
     CHECK(value) << "forgot to set value";
 
-    value->SetWeak(is_weak);
+    value->SetWeak(pb_value.weak());
     DeserializeItemCommon(pb_value, value.get());
     return value;
   }
@@ -350,11 +325,10 @@ class PackagePbDeserializer {
       out_ref->id = ResourceId(pb_ref.id());
     }
 
-    if (pb_ref.has_symbol_idx()) {
-      const std::string str_symbol = util::GetString(*symbol_pool_, pb_ref.symbol_idx());
+    if (pb_ref.has_name()) {
       ResourceNameRef name_ref;
-      if (!ResourceUtils::ParseResourceName(str_symbol, &name_ref, nullptr)) {
-        diag_->Error(DiagMessage(source_) << "invalid reference name '" << str_symbol << "'");
+      if (!ResourceUtils::ParseResourceName(pb_ref.name(), &name_ref, nullptr)) {
+        diag_->Error(DiagMessage(source_) << "invalid reference name '" << pb_ref.name() << "'");
         return false;
       }
 
@@ -377,61 +351,33 @@ class PackagePbDeserializer {
   }
 
  private:
-  const android::ResStringPool* value_pool_;
   const android::ResStringPool* source_pool_;
-  const android::ResStringPool* symbol_pool_;
   const Source source_;
   IDiagnostics* diag_;
 };
 
 }  // namespace
 
-std::unique_ptr<ResourceTable> DeserializeTableFromPb(
-    const pb::ResourceTable& pb_table, const Source& source,
-    IDiagnostics* diag) {
-  // We import the android namespace because on Windows NO_ERROR is a macro, not
-  // an enum, which
+std::unique_ptr<ResourceTable> DeserializeTableFromPb(const pb::ResourceTable& pb_table,
+                                                      const Source& source, IDiagnostics* diag) {
+  // We import the android namespace because on Windows NO_ERROR is a macro, not an enum, which
   // causes errors when qualifying it with android::
   using namespace android;
 
   std::unique_ptr<ResourceTable> table = util::make_unique<ResourceTable>();
 
-  if (!pb_table.has_string_pool()) {
-    diag->Error(DiagMessage(source) << "no string pool found");
-    return {};
-  }
-
-  ResStringPool value_pool;
-  status_t result = value_pool.setTo(pb_table.string_pool().data().data(),
-                                     pb_table.string_pool().data().size());
-  if (result != NO_ERROR) {
-    diag->Error(DiagMessage(source) << "invalid string pool");
-    return {};
-  }
-
   ResStringPool source_pool;
   if (pb_table.has_source_pool()) {
-    result = source_pool.setTo(pb_table.source_pool().data().data(),
-                               pb_table.source_pool().data().size());
+    status_t result = source_pool.setTo(pb_table.source_pool().data().data(),
+                                        pb_table.source_pool().data().size());
     if (result != NO_ERROR) {
       diag->Error(DiagMessage(source) << "invalid source pool");
       return {};
     }
   }
 
-  ResStringPool symbol_pool;
-  if (pb_table.has_symbol_pool()) {
-    result = symbol_pool.setTo(pb_table.symbol_pool().data().data(),
-                               pb_table.symbol_pool().data().size());
-    if (result != NO_ERROR) {
-      diag->Error(DiagMessage(source) << "invalid symbol pool");
-      return {};
-    }
-  }
-
-  PackagePbDeserializer package_pb_deserializer(&value_pool, &source_pool,
-                                                &symbol_pool, source, diag);
-  for (const pb::Package& pb_package : pb_table.packages()) {
+  PackagePbDeserializer package_pb_deserializer(&source_pool, source, diag);
+  for (const pb::Package& pb_package : pb_table.package()) {
     if (!package_pb_deserializer.DeserializeFromPb(pb_package, table.get())) {
       return {};
     }
@@ -440,7 +386,7 @@ std::unique_ptr<ResourceTable> DeserializeTableFromPb(
 }
 
 std::unique_ptr<ResourceFile> DeserializeCompiledFileFromPb(
-    const pb::CompiledFile& pb_file, const Source& source, IDiagnostics* diag) {
+    const pb::internal::CompiledFile& pb_file, const Source& source, IDiagnostics* diag) {
   std::unique_ptr<ResourceFile> file = util::make_unique<ResourceFile>();
 
   ResourceNameRef name_ref;
@@ -456,19 +402,20 @@ std::unique_ptr<ResourceFile> DeserializeCompiledFileFromPb(
   file->source.path = pb_file.source_path();
   DeserializeConfigDescriptionFromPb(pb_file.config(), &file->config);
 
-  for (const pb::CompiledFile_Symbol& pb_symbol : pb_file.exported_symbols()) {
-    // Need to create an lvalue here so that nameRef can point to something
-    // real.
-    if (!ResourceUtils::ParseResourceName(pb_symbol.resource_name(),
-                                          &name_ref)) {
+  for (const pb::internal::CompiledFile_Symbol& pb_symbol : pb_file.exported_symbol()) {
+    // Need to create an lvalue here so that nameRef can point to something real.
+    if (!ResourceUtils::ParseResourceName(pb_symbol.resource_name(), &name_ref)) {
       diag->Error(DiagMessage(source)
                   << "invalid resource name for exported symbol in "
                      "compiled file header: "
                   << pb_file.resource_name());
       return {};
     }
-    file->exported_symbols.push_back(
-        SourcedResourceName{name_ref.ToResourceName(), pb_symbol.line_no()});
+    size_t line = 0u;
+    if (pb_symbol.has_source()) {
+      line = pb_symbol.source().line_number();
+    }
+    file->exported_symbols.push_back(SourcedResourceName{name_ref.ToResourceName(), line});
   }
   return file;
 }
diff --git a/tools/aapt2/proto/TableProtoSerializer.cpp b/tools/aapt2/proto/TableProtoSerializer.cpp
index 730442c62836f..a08df71eae1ea 100644
--- a/tools/aapt2/proto/TableProtoSerializer.cpp
+++ b/tools/aapt2/proto/TableProtoSerializer.cpp
@@ -24,9 +24,9 @@
 
 #include "android-base/logging.h"
 
-using google::protobuf::io::CodedOutputStream;
-using google::protobuf::io::CodedInputStream;
-using google::protobuf::io::ZeroCopyOutputStream;
+using ::google::protobuf::io::CodedInputStream;
+using ::google::protobuf::io::CodedOutputStream;
+using ::google::protobuf::io::ZeroCopyOutputStream;
 
 namespace aapt {
 
@@ -36,46 +36,46 @@ class PbSerializerVisitor : public RawValueVisitor {
  public:
   using RawValueVisitor::Visit;
 
-  /**
-   * Constructor to use when expecting to serialize any value.
-   */
-  PbSerializerVisitor(StringPool* source_pool, StringPool* symbol_pool,
-                      pb::Value* out_pb_value)
-      : source_pool_(source_pool),
-        symbol_pool_(symbol_pool),
-        out_pb_value_(out_pb_value),
-        out_pb_item_(nullptr) {}
+  // Constructor to use when expecting to serialize any value.
+  PbSerializerVisitor(StringPool* source_pool, pb::Value* out_pb_value)
+      : source_pool_(source_pool), out_pb_value_(out_pb_value), out_pb_item_(nullptr) {
+  }
 
-  /**
-   * Constructor to use when expecting to serialize an Item.
-   */
-  PbSerializerVisitor(StringPool* sourcePool, StringPool* symbolPool,
-                      pb::Item* outPbItem)
-      : source_pool_(sourcePool),
-        symbol_pool_(symbolPool),
-        out_pb_value_(nullptr),
-        out_pb_item_(outPbItem) {}
+  // Constructor to use when expecting to serialize an Item.
+  PbSerializerVisitor(StringPool* sourcePool, pb::Item* outPbItem)
+      : source_pool_(sourcePool), out_pb_value_(nullptr), out_pb_item_(outPbItem) {
+  }
 
   void Visit(Reference* ref) override {
     SerializeReferenceToPb(*ref, pb_item()->mutable_ref());
   }
 
   void Visit(String* str) override {
-    pb_item()->mutable_str()->set_idx(str->value.index());
+    pb_item()->mutable_str()->set_value(*str->value);
+  }
+
+  void Visit(RawString* str) override {
+    pb_item()->mutable_raw_str()->set_value(*str->value);
   }
 
   void Visit(StyledString* str) override {
-    pb_item()->mutable_str()->set_idx(str->value.index());
+    pb::StyledString* pb_str = pb_item()->mutable_styled_str();
+    pb_str->set_value(str->value->value);
+
+    for (const StringPool::Span& span : str->value->spans) {
+      pb::StyledString::Span* pb_span = pb_str->add_span();
+      pb_span->set_tag(*span.name);
+      pb_span->set_first_char(span.first_char);
+      pb_span->set_last_char(span.last_char);
+    }
   }
 
   void Visit(FileReference* file) override {
-    pb_item()->mutable_file()->set_path_idx(file->path.index());
+    pb_item()->mutable_file()->set_path(*file->path);
   }
 
-  void Visit(Id* id) override { pb_item()->mutable_id(); }
-
-  void Visit(RawString* raw_str) override {
-    pb_item()->mutable_raw_str()->set_idx(raw_str->value.index());
+  void Visit(Id* /*id*/) override {
+    pb_item()->mutable_id();
   }
 
   void Visit(BinaryPrimitive* prim) override {
@@ -98,7 +98,7 @@ class PbSerializerVisitor : public RawValueVisitor {
     pb_attr->set_max_int(attr->max_int);
 
     for (auto& symbol : attr->symbols) {
-      pb::Attribute_Symbol* pb_symbol = pb_attr->add_symbols();
+      pb::Attribute_Symbol* pb_symbol = pb_attr->add_symbol();
       SerializeItemCommonToPb(symbol.symbol, pb_symbol);
       SerializeReferenceToPb(symbol.symbol, pb_symbol->mutable_name());
       pb_symbol->set_value(symbol.value);
@@ -114,12 +114,12 @@ class PbSerializerVisitor : public RawValueVisitor {
     }
 
     for (Style::Entry& entry : style->entries) {
-      pb::Style_Entry* pb_entry = pb_style->add_entries();
+      pb::Style_Entry* pb_entry = pb_style->add_entry();
       SerializeReferenceToPb(entry.key, pb_entry->mutable_key());
 
       pb::Item* pb_item = pb_entry->mutable_item();
       SerializeItemCommonToPb(entry.key, pb_entry);
-      PbSerializerVisitor sub_visitor(source_pool_, symbol_pool_, pb_item);
+      PbSerializerVisitor sub_visitor(source_pool_, pb_item);
       entry.value->Accept(&sub_visitor);
     }
   }
@@ -127,7 +127,7 @@ class PbSerializerVisitor : public RawValueVisitor {
   void Visit(Styleable* styleable) override {
     pb::Styleable* pb_styleable = pb_compound_value()->mutable_styleable();
     for (Reference& entry : styleable->entries) {
-      pb::Styleable_Entry* pb_entry = pb_styleable->add_entries();
+      pb::Styleable_Entry* pb_entry = pb_styleable->add_entry();
       SerializeItemCommonToPb(entry, pb_entry);
       SerializeReferenceToPb(entry, pb_entry->mutable_attr());
     }
@@ -135,11 +135,10 @@ class PbSerializerVisitor : public RawValueVisitor {
 
   void Visit(Array* array) override {
     pb::Array* pb_array = pb_compound_value()->mutable_array();
-    for (auto& value : array->items) {
-      pb::Array_Entry* pb_entry = pb_array->add_entries();
-      SerializeItemCommonToPb(*value, pb_entry);
-      PbSerializerVisitor sub_visitor(source_pool_, symbol_pool_,
-                                      pb_entry->mutable_item());
+    for (auto& value : array->elements) {
+      pb::Array_Element* pb_element = pb_array->add_element();
+      SerializeItemCommonToPb(*value, pb_element);
+      PbSerializerVisitor sub_visitor(source_pool_, pb_element->mutable_item());
       value->Accept(&sub_visitor);
     }
   }
@@ -153,11 +152,11 @@ class PbSerializerVisitor : public RawValueVisitor {
         continue;
       }
 
-      pb::Plural_Entry* pb_entry = pb_plural->add_entries();
+      pb::Plural_Entry* pb_entry = pb_plural->add_entry();
       pb_entry->set_arity(SerializePluralEnumToPb(i));
       pb::Item* pb_element = pb_entry->mutable_item();
       SerializeItemCommonToPb(*plural->values[i], pb_entry);
-      PbSerializerVisitor sub_visitor(source_pool_, symbol_pool_, pb_element);
+      PbSerializerVisitor sub_visitor(source_pool_, pb_element);
       plural->values[i]->Accept(&sub_visitor);
     }
   }
@@ -179,8 +178,7 @@ class PbSerializerVisitor : public RawValueVisitor {
 
   template <typename T>
   void SerializeItemCommonToPb(const Item& item, T* pb_item) {
-    SerializeSourceToPb(item.GetSource(), source_pool_,
-                        pb_item->mutable_source());
+    SerializeSourceToPb(item.GetSource(), source_pool_, pb_item->mutable_source());
     if (!item.GetComment().empty()) {
       pb_item->set_comment(item.GetComment());
     }
@@ -192,8 +190,7 @@ class PbSerializerVisitor : public RawValueVisitor {
     }
 
     if (ref.name) {
-      StringPool::Ref symbol_ref = symbol_pool_->MakeRef(ref.name.value().ToString());
-      pb_ref->set_symbol_idx(static_cast<uint32_t>(symbol_ref.index()));
+      pb_ref->set_name(ref.name.value().ToString());
     }
 
     pb_ref->set_private_(ref.private_reference);
@@ -201,7 +198,6 @@ class PbSerializerVisitor : public RawValueVisitor {
   }
 
   StringPool* source_pool_;
-  StringPool* symbol_pool_;
   pb::Value* out_pb_value_;
   pb::Item* out_pb_item_;
 };
@@ -220,26 +216,24 @@ std::unique_ptr<pb::ResourceTable> SerializeTableToPb(ResourceTable* table) {
   });
 
   auto pb_table = util::make_unique<pb::ResourceTable>();
-  SerializeStringPoolToPb(table->string_pool, pb_table->mutable_string_pool());
-
-  StringPool source_pool, symbol_pool;
+  StringPool source_pool;
 
   for (auto& package : table->packages) {
-    pb::Package* pb_package = pb_table->add_packages();
+    pb::Package* pb_package = pb_table->add_package();
     if (package->id) {
       pb_package->set_package_id(package->id.value());
     }
     pb_package->set_package_name(package->name);
 
     for (auto& type : package->types) {
-      pb::Type* pb_type = pb_package->add_types();
+      pb::Type* pb_type = pb_package->add_type();
       if (type->id) {
         pb_type->set_id(type->id.value());
       }
       pb_type->set_name(ToString(type->type).to_string());
 
       for (auto& entry : type->entries) {
-        pb::Entry* pb_entry = pb_type->add_entries();
+        pb::Entry* pb_entry = pb_type->add_entry();
         if (entry->id) {
           pb_entry->set_id(entry->id.value());
         }
@@ -253,7 +247,7 @@ std::unique_ptr<pb::ResourceTable> SerializeTableToPb(ResourceTable* table) {
         pb_status->set_allow_new(entry->symbol_status.allow_new);
 
         for (auto& config_value : entry->values) {
-          pb::ConfigValue* pb_config_value = pb_entry->add_config_values();
+          pb::ConfigValue* pb_config_value = pb_entry->add_config_value();
           SerializeConfig(config_value->config, pb_config_value->mutable_config());
           if (!config_value->product.empty()) {
             pb_config_value->mutable_config()->set_product(config_value->product);
@@ -270,7 +264,7 @@ std::unique_ptr<pb::ResourceTable> SerializeTableToPb(ResourceTable* table) {
             pb_value->set_weak(true);
           }
 
-          PbSerializerVisitor visitor(&source_pool, &symbol_pool, pb_value);
+          PbSerializerVisitor visitor(&source_pool, pb_value);
           config_value->value->Accept(&visitor);
         }
       }
@@ -278,27 +272,25 @@ std::unique_ptr<pb::ResourceTable> SerializeTableToPb(ResourceTable* table) {
   }
 
   SerializeStringPoolToPb(source_pool, pb_table->mutable_source_pool());
-  SerializeStringPoolToPb(symbol_pool, pb_table->mutable_symbol_pool());
   return pb_table;
 }
 
-std::unique_ptr<pb::CompiledFile> SerializeCompiledFileToPb(
-    const ResourceFile& file) {
-  auto pb_file = util::make_unique<pb::CompiledFile>();
+std::unique_ptr<pb::internal::CompiledFile> SerializeCompiledFileToPb(const ResourceFile& file) {
+  auto pb_file = util::make_unique<pb::internal::CompiledFile>();
   pb_file->set_resource_name(file.name.ToString());
   pb_file->set_source_path(file.source.path);
   SerializeConfig(file.config, pb_file->mutable_config());
 
   for (const SourcedResourceName& exported : file.exported_symbols) {
-    pb::CompiledFile_Symbol* pb_symbol = pb_file->add_exported_symbols();
+    pb::internal::CompiledFile_Symbol* pb_symbol = pb_file->add_exported_symbol();
     pb_symbol->set_resource_name(exported.name.ToString());
-    pb_symbol->set_line_no(exported.line);
+    pb_symbol->mutable_source()->set_line_number(exported.line);
   }
   return pb_file;
 }
 
-CompiledFileOutputStream::CompiledFileOutputStream(ZeroCopyOutputStream* out)
-    : out_(out) {}
+CompiledFileOutputStream::CompiledFileOutputStream(ZeroCopyOutputStream* out) : out_(out) {
+}
 
 void CompiledFileOutputStream::EnsureAlignedWrite() {
   const int padding = out_.ByteCount() % 4;
@@ -313,8 +305,7 @@ void CompiledFileOutputStream::WriteLittleEndian32(uint32_t val) {
   out_.WriteLittleEndian32(val);
 }
 
-void CompiledFileOutputStream::WriteCompiledFile(
-    const pb::CompiledFile* compiled_file) {
+void CompiledFileOutputStream::WriteCompiledFile(const pb::internal::CompiledFile* compiled_file) {
   EnsureAlignedWrite();
   out_.WriteLittleEndian64(static_cast<uint64_t>(compiled_file->ByteSize()));
   compiled_file->SerializeWithCachedSizes(&out_);
@@ -334,7 +325,9 @@ void CompiledFileOutputStream::WriteData(const void* data, size_t len) {
   out_.WriteRaw(data, len);
 }
 
-bool CompiledFileOutputStream::HadError() { return out_.HadError(); }
+bool CompiledFileOutputStream::HadError() {
+  return out_.HadError();
+}
 
 CompiledFileInputStream::CompiledFileInputStream(const void* data, size_t size)
     : in_(static_cast<const uint8_t*>(data), size) {}
@@ -352,7 +345,7 @@ bool CompiledFileInputStream::ReadLittleEndian32(uint32_t* out_val) {
   return in_.ReadLittleEndian32(out_val);
 }
 
-bool CompiledFileInputStream::ReadCompiledFile(pb::CompiledFile* out_val) {
+bool CompiledFileInputStream::ReadCompiledFile(pb::internal::CompiledFile* out_val) {
   EnsureAlignedRead();
 
   google::protobuf::uint64 pb_size = 0u;
@@ -379,8 +372,7 @@ bool CompiledFileInputStream::ReadCompiledFile(pb::CompiledFile* out_val) {
   return true;
 }
 
-bool CompiledFileInputStream::ReadDataMetaData(uint64_t* out_offset,
-                                               uint64_t* out_len) {
+bool CompiledFileInputStream::ReadDataMetaData(uint64_t* out_offset, uint64_t* out_len) {
   EnsureAlignedRead();
 
   google::protobuf::uint64 pb_size = 0u;
diff --git a/tools/aapt2/proto/TableProtoSerializer_test.cpp b/tools/aapt2/proto/TableProtoSerializer_test.cpp
index 3ebb08eb791e0..80608b3d9c05e 100644
--- a/tools/aapt2/proto/TableProtoSerializer_test.cpp
+++ b/tools/aapt2/proto/TableProtoSerializer_test.cpp
@@ -20,7 +20,9 @@
 #include "test/Test.h"
 
 using ::google::protobuf::io::StringOutputStream;
+using ::testing::Eq;
 using ::testing::NotNull;
+using ::testing::SizeIs;
 
 namespace aapt {
 
@@ -38,12 +40,12 @@ TEST(TableProtoSerializer, SerializeSinglePackage) {
 
   Symbol public_symbol;
   public_symbol.state = SymbolState::kPublic;
-  ASSERT_TRUE(table->SetSymbolState(
-      test::ParseNameOrDie("com.app.a:layout/main"), ResourceId(0x7f020000),
-      public_symbol, context->GetDiagnostics()));
+  ASSERT_TRUE(table->SetSymbolState(test::ParseNameOrDie("com.app.a:layout/main"),
+                                    ResourceId(0x7f020000), public_symbol,
+                                    context->GetDiagnostics()));
 
   Id* id = test::GetValue<Id>(table.get(), "com.app.a:id/foo");
-  ASSERT_NE(nullptr, id);
+  ASSERT_THAT(id, NotNull());
 
   // Make a plural.
   std::unique_ptr<Plural> plural = util::make_unique<Plural>();
@@ -52,6 +54,15 @@ TEST(TableProtoSerializer, SerializeSinglePackage) {
                                  ConfigDescription{}, {}, std::move(plural),
                                  context->GetDiagnostics()));
 
+  // Make a styled string.
+  StyleString style_string;
+  style_string.str = "hello";
+  style_string.spans.push_back(Span{"b", 0u, 4u});
+  ASSERT_TRUE(
+      table->AddResource(test::ParseNameOrDie("com.app.a:string/styled"), ConfigDescription{}, {},
+                         util::make_unique<StyledString>(table->string_pool.MakeRef(style_string)),
+                         context->GetDiagnostics()));
+
   // Make a resource with different products.
   ASSERT_TRUE(table->AddResource(
       test::ParseNameOrDie("com.app.a:integer/one"),
@@ -65,9 +76,8 @@ TEST(TableProtoSerializer, SerializeSinglePackage) {
       context->GetDiagnostics()));
 
   // Make a reference with both resource name and resource ID.
-  // The reference should point to a resource outside of this table to test that
-  // both
-  // name and id get serialized.
+  // The reference should point to a resource outside of this table to test that both name and id
+  // get serialized.
   Reference expected_ref;
   expected_ref.name = test::ParseNameOrDie("android:layout/main");
   expected_ref.id = ResourceId(0x01020000);
@@ -85,36 +95,45 @@ TEST(TableProtoSerializer, SerializeSinglePackage) {
 
   Id* new_id = test::GetValue<Id>(new_table.get(), "com.app.a:id/foo");
   ASSERT_THAT(new_id, NotNull());
-  EXPECT_EQ(id->IsWeak(), new_id->IsWeak());
+  EXPECT_THAT(new_id->IsWeak(), Eq(id->IsWeak()));
 
   Maybe<ResourceTable::SearchResult> result =
       new_table->FindResource(test::ParseNameOrDie("com.app.a:layout/main"));
   ASSERT_TRUE(result);
-  EXPECT_EQ(SymbolState::kPublic, result.value().type->symbol_status.state);
-  EXPECT_EQ(SymbolState::kPublic, result.value().entry->symbol_status.state);
+
+  EXPECT_THAT(result.value().type->symbol_status.state, Eq(SymbolState::kPublic));
+  EXPECT_THAT(result.value().entry->symbol_status.state, Eq(SymbolState::kPublic));
 
   result = new_table->FindResource(test::ParseNameOrDie("com.app.a:bool/foo"));
   ASSERT_TRUE(result);
-  EXPECT_EQ(SymbolState::kUndefined, result.value().entry->symbol_status.state);
+  EXPECT_THAT(result.value().entry->symbol_status.state, Eq(SymbolState::kUndefined));
   EXPECT_TRUE(result.value().entry->symbol_status.allow_new);
 
   // Find the product-dependent values
   BinaryPrimitive* prim = test::GetValueForConfigAndProduct<BinaryPrimitive>(
       new_table.get(), "com.app.a:integer/one", test::ParseConfigOrDie("land"), "");
   ASSERT_THAT(prim, NotNull());
-  EXPECT_EQ(123u, prim->value.data);
+  EXPECT_THAT(prim->value.data, Eq(123u));
 
   prim = test::GetValueForConfigAndProduct<BinaryPrimitive>(
       new_table.get(), "com.app.a:integer/one", test::ParseConfigOrDie("land"), "tablet");
   ASSERT_THAT(prim, NotNull());
-  EXPECT_EQ(321u, prim->value.data);
+  EXPECT_THAT(prim->value.data, Eq(321u));
 
   Reference* actual_ref = test::GetValue<Reference>(new_table.get(), "com.app.a:layout/abc");
   ASSERT_THAT(actual_ref, NotNull());
   ASSERT_TRUE(actual_ref->name);
   ASSERT_TRUE(actual_ref->id);
-  EXPECT_EQ(expected_ref.name.value(), actual_ref->name.value());
-  EXPECT_EQ(expected_ref.id.value(), actual_ref->id.value());
+  EXPECT_THAT(*actual_ref, Eq(expected_ref));
+
+  StyledString* actual_styled_str =
+      test::GetValue<StyledString>(new_table.get(), "com.app.a:string/styled");
+  ASSERT_THAT(actual_styled_str, NotNull());
+  EXPECT_THAT(actual_styled_str->value->value, Eq("hello"));
+  ASSERT_THAT(actual_styled_str->value->spans, SizeIs(1u));
+  EXPECT_THAT(*actual_styled_str->value->spans[0].name, Eq("b"));
+  EXPECT_THAT(actual_styled_str->value->spans[0].first_char, Eq(0u));
+  EXPECT_THAT(actual_styled_str->value->spans[0].last_char, Eq(4u));
 }
 
 TEST(TableProtoSerializer, SerializeFileHeader) {
@@ -132,10 +151,10 @@ TEST(TableProtoSerializer, SerializeFileHeader) {
 
   std::string output_str;
   {
-    std::unique_ptr<pb::CompiledFile> pb_file1 = SerializeCompiledFileToPb(f);
+    std::unique_ptr<pb::internal::CompiledFile> pb_file1 = SerializeCompiledFileToPb(f);
 
     f.name.entry = "__" + f.name.entry + "$0";
-    std::unique_ptr<pb::CompiledFile> pb_file2 = SerializeCompiledFileToPb(f);
+    std::unique_ptr<pb::internal::CompiledFile> pb_file2 = SerializeCompiledFileToPb(f);
 
     StringOutputStream out_stream(&output_str);
     CompiledFileOutputStream out_file_stream(&out_stream);
@@ -154,7 +173,7 @@ TEST(TableProtoSerializer, SerializeFileHeader) {
 
   // Read the first compiled file.
 
-  pb::CompiledFile new_pb_file;
+  pb::internal::CompiledFile new_pb_file;
   ASSERT_TRUE(in_file_stream.ReadCompiledFile(&new_pb_file));
 
   std::unique_ptr<ResourceFile> file = DeserializeCompiledFileFromPb(
@@ -191,7 +210,7 @@ TEST(TableProtoSerializer, SerializeFileHeader) {
 
 TEST(TableProtoSerializer, DeserializeCorruptHeaderSafely) {
   ResourceFile f;
-  std::unique_ptr<pb::CompiledFile> pb_file = SerializeCompiledFileToPb(f);
+  std::unique_ptr<pb::internal::CompiledFile> pb_file = SerializeCompiledFileToPb(f);
 
   const std::string expected_data = "1234";
 
@@ -213,7 +232,7 @@ TEST(TableProtoSerializer, DeserializeCorruptHeaderSafely) {
   EXPECT_TRUE(in_file_stream.ReadLittleEndian32(&num_files));
   EXPECT_EQ(1u, num_files);
 
-  pb::CompiledFile new_pb_file;
+  pb::internal::CompiledFile new_pb_file;
   EXPECT_FALSE(in_file_stream.ReadCompiledFile(&new_pb_file));
 
   uint64_t offset, len;
diff --git a/tools/aapt2/readme.md b/tools/aapt2/readme.md
index c8d36177beb47..8368f9d16af8e 100644
--- a/tools/aapt2/readme.md
+++ b/tools/aapt2/readme.md
@@ -1,5 +1,18 @@
 # Android Asset Packaging Tool 2.0 (AAPT2) release notes
 
+## Version 2.19
+- Added navigation resource type.
+- Fixed issue with resource deduplication. (bug 64397629)
+- Added a daemon mode for issuing commands. This is invoked with `aapt2 daemon`.
+  Command line arguments are separated by newlines, with an empty line signalling the
+  end of a command. Sending `EOF (Ctrl+D)` to the daemon will exit.
+- Fixed an issue where multiple permissions defined in AndroidManifest.xml would generate
+  conflicting definitions for the same Java constant in Manifest.java. Changed the implementation
+  to match that of `aapt`, which will take the last definition as the sole definition.
+  A warning is logged if such a scenario occurs. (bug 64472942)
+- Made improvements to handling of paths on Windows. This should resolve a lot of issues with
+  Unicode paths. (bug 62336414, 63830502)
+
 ## Version 2.18
 ### `aapt2 ...`
 - Fixed issue where enum values were interpreted as integers and range checked. (bug 62358540)
diff --git a/tools/aapt2/test/Builders.cpp b/tools/aapt2/test/Builders.cpp
new file mode 100644
index 0000000000000..8f9788e8a25d5
--- /dev/null
+++ b/tools/aapt2/test/Builders.cpp
@@ -0,0 +1,216 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "test/Builders.h"
+
+#include "android-base/logging.h"
+#include "androidfw/StringPiece.h"
+
+#include "io/StringInputStream.h"
+#include "test/Common.h"
+#include "util/Util.h"
+
+using ::aapt::io::StringInputStream;
+using ::android::StringPiece;
+
+namespace aapt {
+namespace test {
+
+ResourceTableBuilder& ResourceTableBuilder::SetPackageId(const StringPiece& package_name,
+                                                         uint8_t id) {
+  ResourceTablePackage* package = table_->CreatePackage(package_name, id);
+  CHECK(package != nullptr);
+  return *this;
+}
+
+ResourceTableBuilder& ResourceTableBuilder::AddSimple(const StringPiece& name,
+                                                      const ResourceId& id) {
+  return AddValue(name, id, util::make_unique<Id>());
+}
+
+ResourceTableBuilder& ResourceTableBuilder::AddSimple(const StringPiece& name,
+                                                      const ConfigDescription& config,
+                                                      const ResourceId& id) {
+  return AddValue(name, config, id, util::make_unique<Id>());
+}
+
+ResourceTableBuilder& ResourceTableBuilder::AddReference(const StringPiece& name,
+                                                         const StringPiece& ref) {
+  return AddReference(name, {}, ref);
+}
+
+ResourceTableBuilder& ResourceTableBuilder::AddReference(const StringPiece& name,
+                                                         const ResourceId& id,
+                                                         const StringPiece& ref) {
+  return AddValue(name, id, util::make_unique<Reference>(ParseNameOrDie(ref)));
+}
+
+ResourceTableBuilder& ResourceTableBuilder::AddString(const StringPiece& name,
+                                                      const StringPiece& str) {
+  return AddString(name, {}, str);
+}
+
+ResourceTableBuilder& ResourceTableBuilder::AddString(const StringPiece& name, const ResourceId& id,
+                                                      const StringPiece& str) {
+  return AddValue(name, id, util::make_unique<String>(table_->string_pool.MakeRef(str)));
+}
+
+ResourceTableBuilder& ResourceTableBuilder::AddString(const StringPiece& name, const ResourceId& id,
+                                                      const ConfigDescription& config,
+                                                      const StringPiece& str) {
+  return AddValue(name, config, id, util::make_unique<String>(table_->string_pool.MakeRef(str)));
+}
+
+ResourceTableBuilder& ResourceTableBuilder::AddFileReference(const StringPiece& name,
+                                                             const StringPiece& path) {
+  return AddFileReference(name, {}, path);
+}
+
+ResourceTableBuilder& ResourceTableBuilder::AddFileReference(const StringPiece& name,
+                                                             const ResourceId& id,
+                                                             const StringPiece& path) {
+  return AddValue(name, id, util::make_unique<FileReference>(table_->string_pool.MakeRef(path)));
+}
+
+ResourceTableBuilder& ResourceTableBuilder::AddFileReference(const StringPiece& name,
+                                                             const StringPiece& path,
+                                                             const ConfigDescription& config) {
+  return AddValue(name, config, {},
+                  util::make_unique<FileReference>(table_->string_pool.MakeRef(path)));
+}
+
+ResourceTableBuilder& ResourceTableBuilder::AddValue(const StringPiece& name,
+                                                     std::unique_ptr<Value> value) {
+  return AddValue(name, {}, std::move(value));
+}
+
+ResourceTableBuilder& ResourceTableBuilder::AddValue(const StringPiece& name, const ResourceId& id,
+                                                     std::unique_ptr<Value> value) {
+  return AddValue(name, {}, id, std::move(value));
+}
+
+ResourceTableBuilder& ResourceTableBuilder::AddValue(const StringPiece& name,
+                                                     const ConfigDescription& config,
+                                                     const ResourceId& id,
+                                                     std::unique_ptr<Value> value) {
+  ResourceName res_name = ParseNameOrDie(name);
+  CHECK(table_->AddResourceAllowMangled(res_name, id, config, {}, std::move(value),
+                                        GetDiagnostics()));
+  return *this;
+}
+
+ResourceTableBuilder& ResourceTableBuilder::SetSymbolState(const StringPiece& name,
+                                                           const ResourceId& id, SymbolState state,
+                                                           bool allow_new) {
+  ResourceName res_name = ParseNameOrDie(name);
+  Symbol symbol;
+  symbol.state = state;
+  symbol.allow_new = allow_new;
+  CHECK(table_->SetSymbolStateAllowMangled(res_name, id, symbol, GetDiagnostics()));
+  return *this;
+}
+
+StringPool* ResourceTableBuilder::string_pool() {
+  return &table_->string_pool;
+}
+
+std::unique_ptr<ResourceTable> ResourceTableBuilder::Build() {
+  return std::move(table_);
+}
+
+std::unique_ptr<Reference> BuildReference(const StringPiece& ref, const Maybe<ResourceId>& id) {
+  std::unique_ptr<Reference> reference = util::make_unique<Reference>(ParseNameOrDie(ref));
+  reference->id = id;
+  return reference;
+}
+
+std::unique_ptr<BinaryPrimitive> BuildPrimitive(uint8_t type, uint32_t data) {
+  android::Res_value value = {};
+  value.size = sizeof(value);
+  value.dataType = type;
+  value.data = data;
+  return util::make_unique<BinaryPrimitive>(value);
+}
+
+AttributeBuilder::AttributeBuilder(bool weak) : attr_(util::make_unique<Attribute>(weak)) {
+  attr_->type_mask = android::ResTable_map::TYPE_ANY;
+}
+
+AttributeBuilder& AttributeBuilder::SetTypeMask(uint32_t typeMask) {
+  attr_->type_mask = typeMask;
+  return *this;
+}
+
+AttributeBuilder& AttributeBuilder::AddItem(const StringPiece& name, uint32_t value) {
+  attr_->symbols.push_back(
+      Attribute::Symbol{Reference(ResourceName({}, ResourceType::kId, name)), value});
+  return *this;
+}
+
+std::unique_ptr<Attribute> AttributeBuilder::Build() {
+  return std::move(attr_);
+}
+
+StyleBuilder& StyleBuilder::SetParent(const StringPiece& str) {
+  style_->parent = Reference(ParseNameOrDie(str));
+  return *this;
+}
+
+StyleBuilder& StyleBuilder::AddItem(const StringPiece& str, std::unique_ptr<Item> value) {
+  style_->entries.push_back(Style::Entry{Reference(ParseNameOrDie(str)), std::move(value)});
+  return *this;
+}
+
+StyleBuilder& StyleBuilder::AddItem(const StringPiece& str, const ResourceId& id,
+                                    std::unique_ptr<Item> value) {
+  AddItem(str, std::move(value));
+  style_->entries.back().key.id = id;
+  return *this;
+}
+
+std::unique_ptr<Style> StyleBuilder::Build() {
+  return std::move(style_);
+}
+
+StyleableBuilder& StyleableBuilder::AddItem(const StringPiece& str, const Maybe<ResourceId>& id) {
+  styleable_->entries.push_back(Reference(ParseNameOrDie(str)));
+  styleable_->entries.back().id = id;
+  return *this;
+}
+
+std::unique_ptr<Styleable> StyleableBuilder::Build() {
+  return std::move(styleable_);
+}
+
+std::unique_ptr<xml::XmlResource> BuildXmlDom(const StringPiece& str) {
+  std::string input = "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
+  input.append(str.data(), str.size());
+  StringInputStream in(input);
+  StdErrDiagnostics diag;
+  std::unique_ptr<xml::XmlResource> doc = xml::Inflate(&in, &diag, Source("test.xml"));
+  CHECK(doc != nullptr && doc->root != nullptr) << "failed to parse inline XML string";
+  return doc;
+}
+
+std::unique_ptr<xml::XmlResource> BuildXmlDomForPackageName(IAaptContext* context,
+                                                            const StringPiece& str) {
+  std::unique_ptr<xml::XmlResource> doc = BuildXmlDom(str);
+  doc->file.name.package = context->GetCompilationPackage();
+  return doc;
+}
+
+}  // namespace test
+}  // namespace aapt
diff --git a/tools/aapt2/test/Builders.h b/tools/aapt2/test/Builders.h
index 6b82076474717..d9f3912fb4c66 100644
--- a/tools/aapt2/test/Builders.h
+++ b/tools/aapt2/test/Builders.h
@@ -19,13 +19,13 @@
 
 #include <memory>
 
-#include "android-base/logging.h"
 #include "android-base/macros.h"
 
+#include "Resource.h"
 #include "ResourceTable.h"
 #include "ResourceValues.h"
-#include "test/Common.h"
-#include "util/Util.h"
+#include "process/IResourceTableConsumer.h"
+#include "util/Maybe.h"
 #include "xml/XmlDom.h"
 
 namespace aapt {
@@ -35,97 +35,37 @@ class ResourceTableBuilder {
  public:
   ResourceTableBuilder() = default;
 
-  StringPool* string_pool() { return &table_->string_pool; }
-
-  ResourceTableBuilder& SetPackageId(const android::StringPiece& package_name, uint8_t id) {
-    ResourceTablePackage* package = table_->CreatePackage(package_name, id);
-    CHECK(package != nullptr);
-    return *this;
-  }
-
-  ResourceTableBuilder& AddSimple(const android::StringPiece& name, const ResourceId& id = {}) {
-    return AddValue(name, id, util::make_unique<Id>());
-  }
-
+  ResourceTableBuilder& SetPackageId(const android::StringPiece& package_name, uint8_t id);
+  ResourceTableBuilder& AddSimple(const android::StringPiece& name, const ResourceId& id = {});
   ResourceTableBuilder& AddSimple(const android::StringPiece& name, const ConfigDescription& config,
-                                  const ResourceId& id = {}) {
-    return AddValue(name, config, id, util::make_unique<Id>());
-  }
-
+                                  const ResourceId& id = {});
   ResourceTableBuilder& AddReference(const android::StringPiece& name,
-                                     const android::StringPiece& ref) {
-    return AddReference(name, {}, ref);
-  }
-
+                                     const android::StringPiece& ref);
   ResourceTableBuilder& AddReference(const android::StringPiece& name, const ResourceId& id,
-                                     const android::StringPiece& ref) {
-    return AddValue(name, id, util::make_unique<Reference>(ParseNameOrDie(ref)));
-  }
-
+                                     const android::StringPiece& ref);
   ResourceTableBuilder& AddString(const android::StringPiece& name,
-                                  const android::StringPiece& str) {
-    return AddString(name, {}, str);
-  }
-
+                                  const android::StringPiece& str);
   ResourceTableBuilder& AddString(const android::StringPiece& name, const ResourceId& id,
-                                  const android::StringPiece& str) {
-    return AddValue(
-        name, id, util::make_unique<String>(table_->string_pool.MakeRef(str)));
-  }
-
+                                  const android::StringPiece& str);
   ResourceTableBuilder& AddString(const android::StringPiece& name, const ResourceId& id,
-                                  const ConfigDescription& config,
-                                  const android::StringPiece& str) {
-    return AddValue(name, config, id, util::make_unique<String>(
-                                          table_->string_pool.MakeRef(str)));
-  }
-
+                                  const ConfigDescription& config, const android::StringPiece& str);
   ResourceTableBuilder& AddFileReference(const android::StringPiece& name,
-                                         const android::StringPiece& path) {
-    return AddFileReference(name, {}, path);
-  }
-
+                                         const android::StringPiece& path);
   ResourceTableBuilder& AddFileReference(const android::StringPiece& name, const ResourceId& id,
-                                         const android::StringPiece& path) {
-    return AddValue(name, id, util::make_unique<FileReference>(
-                                  table_->string_pool.MakeRef(path)));
-  }
-
+                                         const android::StringPiece& path);
   ResourceTableBuilder& AddFileReference(const android::StringPiece& name,
                                          const android::StringPiece& path,
-                                         const ConfigDescription& config) {
-    return AddValue(name, config, {}, util::make_unique<FileReference>(
-                                          table_->string_pool.MakeRef(path)));
-  }
-
-  ResourceTableBuilder& AddValue(const android::StringPiece& name, std::unique_ptr<Value> value) {
-    return AddValue(name, {}, std::move(value));
-  }
-
+                                         const ConfigDescription& config);
+  ResourceTableBuilder& AddValue(const android::StringPiece& name, std::unique_ptr<Value> value);
   ResourceTableBuilder& AddValue(const android::StringPiece& name, const ResourceId& id,
-                                 std::unique_ptr<Value> value) {
-    return AddValue(name, {}, id, std::move(value));
-  }
-
+                                 std::unique_ptr<Value> value);
   ResourceTableBuilder& AddValue(const android::StringPiece& name, const ConfigDescription& config,
-                                 const ResourceId& id, std::unique_ptr<Value> value) {
-    ResourceName res_name = ParseNameOrDie(name);
-    CHECK(table_->AddResourceAllowMangled(res_name, id, config, {}, std::move(value),
-                                          GetDiagnostics()));
-    return *this;
-  }
-
+                                 const ResourceId& id, std::unique_ptr<Value> value);
   ResourceTableBuilder& SetSymbolState(const android::StringPiece& name, const ResourceId& id,
-                                       SymbolState state, bool allow_new = false) {
-    ResourceName res_name = ParseNameOrDie(name);
-    Symbol symbol;
-    symbol.state = state;
-    symbol.allow_new = allow_new;
-    CHECK(table_->SetSymbolStateAllowMangled(res_name, id, symbol, GetDiagnostics()));
-    return *this;
-  }
+                                       SymbolState state, bool allow_new = false);
 
-  std::unique_ptr<ResourceTable> Build() { return std::move(table_); }
+  StringPool* string_pool();
+  std::unique_ptr<ResourceTable> Build();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ResourceTableBuilder);
@@ -133,29 +73,16 @@ class ResourceTableBuilder {
   std::unique_ptr<ResourceTable> table_ = util::make_unique<ResourceTable>();
 };
 
-inline std::unique_ptr<Reference> BuildReference(const android::StringPiece& ref,
-                                                 const Maybe<ResourceId>& id = {}) {
-  std::unique_ptr<Reference> reference =
-      util::make_unique<Reference>(ParseNameOrDie(ref));
-  reference->id = id;
-  return reference;
-}
-
-inline std::unique_ptr<BinaryPrimitive> BuildPrimitive(uint8_t type,
-                                                       uint32_t data) {
-  android::Res_value value = {};
-  value.size = sizeof(value);
-  value.dataType = type;
-  value.data = data;
-  return util::make_unique<BinaryPrimitive>(value);
-}
+std::unique_ptr<Reference> BuildReference(const android::StringPiece& ref,
+                                          const Maybe<ResourceId>& id = {});
+std::unique_ptr<BinaryPrimitive> BuildPrimitive(uint8_t type, uint32_t data);
 
 template <typename T>
 class ValueBuilder {
  public:
   template <typename... Args>
-  explicit ValueBuilder(Args&&... args)
-      : value_(new T{std::forward<Args>(args)...}) {}
+  explicit ValueBuilder(Args&&... args) : value_(new T{std::forward<Args>(args)...}) {
+  }
 
   template <typename... Args>
   ValueBuilder& SetSource(Args&&... args) {
@@ -168,7 +95,9 @@ class ValueBuilder {
     return *this;
   }
 
-  std::unique_ptr<Value> Build() { return std::move(value_); }
+  std::unique_ptr<Value> Build() {
+    return std::move(value_);
+  }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ValueBuilder);
@@ -178,23 +107,10 @@ class ValueBuilder {
 
 class AttributeBuilder {
  public:
-  explicit AttributeBuilder(bool weak = false)
-      : attr_(util::make_unique<Attribute>(weak)) {
-    attr_->type_mask = android::ResTable_map::TYPE_ANY;
-  }
-
-  AttributeBuilder& SetTypeMask(uint32_t typeMask) {
-    attr_->type_mask = typeMask;
-    return *this;
-  }
-
-  AttributeBuilder& AddItem(const android::StringPiece& name, uint32_t value) {
-    attr_->symbols.push_back(Attribute::Symbol{
-        Reference(ResourceName({}, ResourceType::kId, name)), value});
-    return *this;
-  }
-
-  std::unique_ptr<Attribute> Build() { return std::move(attr_); }
+  explicit AttributeBuilder(bool weak = false);
+  AttributeBuilder& SetTypeMask(uint32_t typeMask);
+  AttributeBuilder& AddItem(const android::StringPiece& name, uint32_t value);
+  std::unique_ptr<Attribute> Build();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AttributeBuilder);
@@ -205,27 +121,11 @@ class AttributeBuilder {
 class StyleBuilder {
  public:
   StyleBuilder() = default;
-
-  StyleBuilder& SetParent(const android::StringPiece& str) {
-    style_->parent = Reference(ParseNameOrDie(str));
-    return *this;
-  }
-
-  StyleBuilder& AddItem(const android::StringPiece& str, std::unique_ptr<Item> value) {
-    style_->entries.push_back(Style::Entry{Reference(ParseNameOrDie(str)), std::move(value)});
-    return *this;
-  }
-
+  StyleBuilder& SetParent(const android::StringPiece& str);
+  StyleBuilder& AddItem(const android::StringPiece& str, std::unique_ptr<Item> value);
   StyleBuilder& AddItem(const android::StringPiece& str, const ResourceId& id,
-                        std::unique_ptr<Item> value) {
-    AddItem(str, std::move(value));
-    style_->entries.back().key.id = id;
-    return *this;
-  }
-
-  std::unique_ptr<Style> Build() {
-    return std::move(style_);
-  }
+                        std::unique_ptr<Item> value);
+  std::unique_ptr<Style> Build();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(StyleBuilder);
@@ -236,14 +136,8 @@ class StyleBuilder {
 class StyleableBuilder {
  public:
   StyleableBuilder() = default;
-
-  StyleableBuilder& AddItem(const android::StringPiece& str, const Maybe<ResourceId>& id = {}) {
-    styleable_->entries.push_back(Reference(ParseNameOrDie(str)));
-    styleable_->entries.back().id = id;
-    return *this;
-  }
-
-  std::unique_ptr<Styleable> Build() { return std::move(styleable_); }
+  StyleableBuilder& AddItem(const android::StringPiece& str, const Maybe<ResourceId>& id = {});
+  std::unique_ptr<Styleable> Build();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(StyleableBuilder);
@@ -251,22 +145,9 @@ class StyleableBuilder {
   std::unique_ptr<Styleable> styleable_ = util::make_unique<Styleable>();
 };
 
-inline std::unique_ptr<xml::XmlResource> BuildXmlDom(const android::StringPiece& str) {
-  std::stringstream in;
-  in << "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n" << str;
-  StdErrDiagnostics diag;
-  std::unique_ptr<xml::XmlResource> doc =
-      xml::Inflate(&in, &diag, Source("test.xml"));
-  CHECK(doc != nullptr) << "failed to parse inline XML string";
-  return doc;
-}
-
-inline std::unique_ptr<xml::XmlResource> BuildXmlDomForPackageName(
-    IAaptContext* context, const android::StringPiece& str) {
-  std::unique_ptr<xml::XmlResource> doc = BuildXmlDom(str);
-  doc->file.name.package = context->GetCompilationPackage();
-  return doc;
-}
+std::unique_ptr<xml::XmlResource> BuildXmlDom(const android::StringPiece& str);
+std::unique_ptr<xml::XmlResource> BuildXmlDomForPackageName(IAaptContext* context,
+                                                            const android::StringPiece& str);
 
 }  // namespace test
 }  // namespace aapt
diff --git a/tools/aapt2/test/Common.h b/tools/aapt2/test/Common.h
index d7b46caf8c941..e6b38c0007b4f 100644
--- a/tools/aapt2/test/Common.h
+++ b/tools/aapt2/test/Common.h
@@ -142,10 +142,97 @@ MATCHER_P(StrEq, a,
   return android::StringPiece16(arg) == a;
 }
 
-MATCHER_P(ValueEq, a,
-          std::string(negation ? "isn't" : "is") + " equal to " + ::testing::PrintToString(a)) {
-  return arg.Equals(&a);
-}
+class ValueEq {
+ public:
+  template <typename arg_type>
+  class BaseImpl : public ::testing::MatcherInterface<arg_type> {
+    BaseImpl(const BaseImpl&) = default;
+
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "is equal to " << *expected_;
+    }
+
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << "is not equal to " << *expected_;
+    }
+
+   protected:
+    BaseImpl(const Value* expected) : expected_(expected) {
+    }
+
+    const Value* expected_;
+  };
+
+  template <typename T, bool>
+  class Impl {};
+
+  template <typename T>
+  class Impl<T, false> : public ::testing::MatcherInterface<T> {
+   public:
+    explicit Impl(const Value* expected) : expected_(expected) {
+    }
+
+    bool MatchAndExplain(T x, ::testing::MatchResultListener* listener) const override {
+      return expected_->Equals(&x);
+    }
+
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "is equal to " << *expected_;
+    }
+
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << "is not equal to " << *expected_;
+    }
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(Impl);
+
+    const Value* expected_;
+  };
+
+  template <typename T>
+  class Impl<T, true> : public ::testing::MatcherInterface<T> {
+   public:
+    explicit Impl(const Value* expected) : expected_(expected) {
+    }
+
+    bool MatchAndExplain(T x, ::testing::MatchResultListener* listener) const override {
+      return expected_->Equals(x);
+    }
+
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "is equal to " << *expected_;
+    }
+
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << "is not equal to " << *expected_;
+    }
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(Impl);
+
+    const Value* expected_;
+  };
+
+  ValueEq(const Value& expected) : expected_(&expected) {
+  }
+  ValueEq(const Value* expected) : expected_(expected) {
+  }
+  ValueEq(const ValueEq&) = default;
+
+  template <typename T>
+  operator ::testing::Matcher<T>() const {
+    return ::testing::Matcher<T>(new Impl<T, std::is_pointer<T>::value>(expected_));
+  }
+
+ private:
+  const Value* expected_;
+};
+
+// MATCHER_P(ValueEq, a,
+//          std::string(negation ? "isn't" : "is") + " equal to " + ::testing::PrintToString(a)) {
+//  return arg.Equals(&a);
+//}
 
 MATCHER_P(StrValueEq, a,
           std::string(negation ? "isn't" : "is") + " equal to " + ::testing::PrintToString(a)) {
diff --git a/tools/aapt2/unflatten/BinaryResourceParser.cpp b/tools/aapt2/unflatten/BinaryResourceParser.cpp
index 728d1f4207c44..892aee6fadcbf 100644
--- a/tools/aapt2/unflatten/BinaryResourceParser.cpp
+++ b/tools/aapt2/unflatten/BinaryResourceParser.cpp
@@ -544,7 +544,7 @@ std::unique_ptr<Array> BinaryResourceParser::ParseArray(
     const ResTable_map_entry* map) {
   std::unique_ptr<Array> array = util::make_unique<Array>();
   for (const ResTable_map& map_entry : map) {
-    array->items.push_back(ParseValue(name, config, map_entry.value));
+    array->elements.push_back(ParseValue(name, config, map_entry.value));
   }
   return array;
 }
diff --git a/tools/aapt2/util/Files.cpp b/tools/aapt2/util/Files.cpp
index 1bf25947ea931..bf8dc4d727f76 100644
--- a/tools/aapt2/util/Files.cpp
+++ b/tools/aapt2/util/Files.cpp
@@ -27,6 +27,8 @@
 #include "android-base/errors.h"
 #include "android-base/file.h"
 #include "android-base/logging.h"
+#include "android-base/unique_fd.h"
+#include "android-base/utf8.h"
 
 #include "util/Util.h"
 
@@ -35,14 +37,32 @@
 #include <direct.h>
 #endif
 
-using android::StringPiece;
+using ::android::FileMap;
+using ::android::StringPiece;
+using ::android::base::ReadFileToString;
+using ::android::base::SystemErrorCodeToString;
+using ::android::base::unique_fd;
 
 namespace aapt {
 namespace file {
 
-FileType GetFileType(const StringPiece& path) {
+FileType GetFileType(const std::string& path) {
+// TODO(adamlesinski): I'd like to move this to ::android::base::utf8 but Windows does some macro
+// trickery with 'stat' and things don't override very well.
+#ifdef _WIN32
+  std::wstring path_utf16;
+  if (!::android::base::UTF8PathToWindowsLongPath(path.c_str(), &path_utf16)) {
+    return FileType::kNonexistant;
+  }
+
+  struct _stat64 sb;
+  int result = _wstat64(path_utf16.c_str(), &sb);
+#else
   struct stat sb;
-  if (stat(path.data(), &sb) < 0) {
+  int result = stat(path.c_str(), &sb);
+#endif
+
+  if (result == -1) {
     if (errno == ENOENT || errno == ENOTDIR) {
       return FileType::kNonexistant;
     }
@@ -72,27 +92,20 @@ FileType GetFileType(const StringPiece& path) {
   }
 }
 
-inline static int MkdirImpl(const StringPiece& path) {
-#ifdef _WIN32
-  return _mkdir(path.to_string().c_str());
-#else
-  return mkdir(path.to_string().c_str(), S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP);
-#endif
-}
-
-bool mkdirs(const StringPiece& path) {
-  const char* start = path.begin();
-  const char* end = path.end();
-  for (const char* current = start; current != end; ++current) {
-    if (*current == sDirSep && current != start) {
-      StringPiece parent_path(start, current - start);
-      int result = MkdirImpl(parent_path);
-      if (result < 0 && errno != EEXIST) {
-        return false;
-      }
+bool mkdirs(const std::string& path) {
+  constexpr const mode_t mode = S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP;
+  // Start after the first character so that we don't consume the root '/'.
+  // This is safe to do with unicode because '/' will never match with a continuation character.
+  size_t current_pos = 1u;
+  while ((current_pos = path.find(sDirSep, current_pos)) != std::string::npos) {
+    std::string parent_path = path.substr(0, current_pos);
+    int result = ::android::base::utf8::mkdir(parent_path.c_str(), mode);
+    if (result < 0 && errno != EEXIST) {
+      return false;
     }
+    current_pos += 1;
   }
-  return MkdirImpl(path) == 0 || errno == EEXIST;
+  return ::android::base::utf8::mkdir(path.c_str(), mode) == 0 || errno == EEXIST;
 }
 
 StringPiece GetStem(const StringPiece& path) {
@@ -129,10 +142,8 @@ StringPiece GetExtension(const StringPiece& path) {
 
 void AppendPath(std::string* base, StringPiece part) {
   CHECK(base != nullptr);
-  const bool base_has_trailing_sep =
-      (!base->empty() && *(base->end() - 1) == sDirSep);
-  const bool part_has_leading_sep =
-      (!part.empty() && *(part.begin()) == sDirSep);
+  const bool base_has_trailing_sep = (!base->empty() && *(base->end() - 1) == sDirSep);
+  const bool part_has_leading_sep = (!part.empty() && *(part.begin()) == sDirSep);
   if (base_has_trailing_sep && part_has_leading_sep) {
     // Remove the part's leading sep
     part = part.substr(1, part.size() - 1);
@@ -151,31 +162,34 @@ std::string PackageToPath(const StringPiece& package) {
   return out_path;
 }
 
-Maybe<android::FileMap> MmapPath(const StringPiece& path,
-                                 std::string* out_error) {
-  std::unique_ptr<FILE, decltype(fclose)*> f = {fopen(path.data(), "rb"),
-                                                fclose};
-  if (!f) {
-    if (out_error) *out_error = android::base::SystemErrorCodeToString(errno);
+Maybe<FileMap> MmapPath(const std::string& path, std::string* out_error) {
+  int flags = O_RDONLY | O_CLOEXEC | O_BINARY;
+  unique_fd fd(TEMP_FAILURE_RETRY(::android::base::utf8::open(path.c_str(), flags)));
+  if (fd == -1) {
+    if (out_error) {
+      *out_error = SystemErrorCodeToString(errno);
+    }
     return {};
   }
 
-  int fd = fileno(f.get());
-
   struct stat filestats = {};
   if (fstat(fd, &filestats) != 0) {
-    if (out_error) *out_error = android::base::SystemErrorCodeToString(errno);
+    if (out_error) {
+      *out_error = SystemErrorCodeToString(errno);
+    }
     return {};
   }
 
-  android::FileMap filemap;
+  FileMap filemap;
   if (filestats.st_size == 0) {
     // mmap doesn't like a length of 0. Instead we return an empty FileMap.
     return std::move(filemap);
   }
 
-  if (!filemap.create(path.data(), fd, 0, filestats.st_size, true)) {
-    if (out_error) *out_error = android::base::SystemErrorCodeToString(errno);
+  if (!filemap.create(path.c_str(), fd, 0, filestats.st_size, true)) {
+    if (out_error) {
+      *out_error = SystemErrorCodeToString(errno);
+    }
     return {};
   }
   return std::move(filemap);
@@ -184,7 +198,7 @@ Maybe<android::FileMap> MmapPath(const StringPiece& path,
 bool AppendArgsFromFile(const StringPiece& path, std::vector<std::string>* out_arglist,
                         std::string* out_error) {
   std::string contents;
-  if (!android::base::ReadFileToString(path.to_string(), &contents, true /*follow_symlinks*/)) {
+  if (!ReadFileToString(path.to_string(), &contents, true /*follow_symlinks*/)) {
     if (out_error) {
       *out_error = "failed to read argument-list file";
     }
@@ -270,7 +284,7 @@ Maybe<std::vector<std::string>> FindFiles(const android::StringPiece& path, IDia
   const std::string root_dir = path.to_string();
   std::unique_ptr<DIR, decltype(closedir)*> d(opendir(root_dir.data()), closedir);
   if (!d) {
-    diag->Error(DiagMessage() << android::base::SystemErrorCodeToString(errno));
+    diag->Error(DiagMessage() << SystemErrorCodeToString(errno));
     return {};
   }
 
diff --git a/tools/aapt2/util/Files.h b/tools/aapt2/util/Files.h
index b3b1e484d27b6..b26e4fa26de6d 100644
--- a/tools/aapt2/util/Files.h
+++ b/tools/aapt2/util/Files.h
@@ -34,8 +34,10 @@ namespace file {
 
 #ifdef _WIN32
 constexpr const char sDirSep = '\\';
+constexpr const char sPathSep = ';';
 #else
 constexpr const char sDirSep = '/';
+constexpr const char sPathSep = ':';
 #endif
 
 enum class FileType {
@@ -50,79 +52,56 @@ enum class FileType {
   kSocket,
 };
 
-FileType GetFileType(const android::StringPiece& path);
+FileType GetFileType(const std::string& path);
 
-/*
- * Appends a path to `base`, separated by the directory separator.
- */
+// Appends a path to `base`, separated by the directory separator.
 void AppendPath(std::string* base, android::StringPiece part);
 
-/*
- * Makes all the directories in `path`. The last element in the path
- * is interpreted as a directory.
- */
-bool mkdirs(const android::StringPiece& path);
+// Makes all the directories in `path`. The last element in the path is interpreted as a directory.
+bool mkdirs(const std::string& path);
 
-/**
- * Returns all but the last part of the path.
- */
+// Returns all but the last part of the path.
 android::StringPiece GetStem(const android::StringPiece& path);
 
-/**
- * Returns the last part of the path with extension.
- */
+// Returns the last part of the path with extension.
 android::StringPiece GetFilename(const android::StringPiece& path);
 
-/**
- * Returns the extension of the path. This is the entire string after
- * the first '.' of the last part of the path.
- */
+// Returns the extension of the path. This is the entire string after the first '.' of the last part
+// of the path.
 android::StringPiece GetExtension(const android::StringPiece& path);
 
-/**
- * Converts a package name (com.android.app) to a path: com/android/app
- */
+// Converts a package name (com.android.app) to a path: com/android/app
 std::string PackageToPath(const android::StringPiece& package);
 
-/**
- * Creates a FileMap for the file at path.
- */
-Maybe<android::FileMap> MmapPath(const android::StringPiece& path, std::string* out_error);
+// Creates a FileMap for the file at path.
+Maybe<android::FileMap> MmapPath(const std::string& path, std::string* out_error);
 
-/**
- * Reads the file at path and appends each line to the outArgList vector.
- */
+// Reads the file at path and appends each line to the outArgList vector.
 bool AppendArgsFromFile(const android::StringPiece& path, std::vector<std::string>* out_arglist,
                         std::string* out_error);
 
-/*
- * Filter that determines which resource files/directories are
- * processed by AAPT. Takes a pattern string supplied by the user.
- * Pattern format is specified in the FileFilter::SetPattern() method.
- */
+// Filter that determines which resource files/directories are
+// processed by AAPT. Takes a pattern string supplied by the user.
+// Pattern format is specified in the FileFilter::SetPattern() method.
 class FileFilter {
  public:
   explicit FileFilter(IDiagnostics* diag) : diag_(diag) {}
 
-  /*
-   * Patterns syntax:
-   * - Delimiter is :
-   * - Entry can start with the flag ! to avoid printing a warning
-   *   about the file being ignored.
-   * - Entry can have the flag "<dir>" to match only directories
-   *   or <file> to match only files. Default is to match both.
-   * - Entry can be a simplified glob "<prefix>*" or "*<suffix>"
-   *   where prefix/suffix must have at least 1 character (so that
-   *   we don't match a '*' catch-all pattern.)
-   * - The special filenames "." and ".." are always ignored.
-   * - Otherwise the full string is matched.
-   * - match is not case-sensitive.
-   */
+  // Patterns syntax:
+  // - Delimiter is :
+  // - Entry can start with the flag ! to avoid printing a warning
+  //   about the file being ignored.
+  // - Entry can have the flag "<dir>" to match only directories
+  //   or <file> to match only files. Default is to match both.
+  // - Entry can be a simplified glob "<prefix>*" or "*<suffix>"
+  //   where prefix/suffix must have at least 1 character (so that
+  //   we don't match a '*' catch-all pattern.)
+  // - The special filenames "." and ".." are always ignored.
+  // - Otherwise the full string is matched.
+  // - match is not case-sensitive.
   bool SetPattern(const android::StringPiece& pattern);
 
-  /**
-   * Applies the filter, returning true for pass, false for fail.
-   */
+  // Applies the filter, returning true for pass, false for fail.
   bool operator()(const std::string& filename, FileType type) const;
 
  private:
diff --git a/tools/aapt2/util/Util.h b/tools/aapt2/util/Util.h
index ad3989ea430f5..8f021ab8cb8a4 100644
--- a/tools/aapt2/util/Util.h
+++ b/tools/aapt2/util/Util.h
@@ -228,6 +228,12 @@ class Tokenizer {
  public:
   class iterator {
    public:
+    using reference = android::StringPiece&;
+    using value_type = android::StringPiece;
+    using difference_type = size_t;
+    using pointer = android::StringPiece*;
+    using iterator_category = std::forward_iterator_tag;
+
     iterator(const iterator&) = default;
     iterator& operator=(const iterator&) = default;
 
@@ -250,9 +256,13 @@ class Tokenizer {
 
   Tokenizer(android::StringPiece str, char sep);
 
-  iterator begin() { return begin_; }
+  iterator begin() const {
+    return begin_;
+  }
 
-  iterator end() { return end_; }
+  iterator end() const {
+    return end_;
+  }
 
  private:
   const iterator begin_;
diff --git a/tools/aapt2/xml/XmlActionExecutor.cpp b/tools/aapt2/xml/XmlActionExecutor.cpp
index 352a933616333..cc664a5de7224 100644
--- a/tools/aapt2/xml/XmlActionExecutor.cpp
+++ b/tools/aapt2/xml/XmlActionExecutor.cpp
@@ -78,7 +78,7 @@ bool XmlActionExecutor::Execute(XmlActionExecutorPolicy policy, IDiagnostics* di
                                 XmlResource* doc) const {
   SourcePathDiagnostics source_diag(doc->file.source, diag);
 
-  Element* el = FindRootElement(doc);
+  Element* el = doc->root.get();
   if (!el) {
     if (policy == XmlActionExecutorPolicy::kWhitelist) {
       source_diag.Error(DiagMessage() << "no root XML tag found");
diff --git a/tools/aapt2/xml/XmlDom.cpp b/tools/aapt2/xml/XmlDom.cpp
index 885ab3e33fedd..cbb652ed9a1a2 100644
--- a/tools/aapt2/xml/XmlDom.cpp
+++ b/tools/aapt2/xml/XmlDom.cpp
@@ -29,8 +29,9 @@
 #include "XmlPullParser.h"
 #include "util/Util.h"
 
-using android::StringPiece;
-using android::StringPiece16;
+using ::aapt::io::InputStream;
+using ::android::StringPiece;
+using ::android::StringPiece16;
 
 namespace aapt {
 namespace xml {
@@ -38,17 +39,15 @@ namespace xml {
 constexpr char kXmlNamespaceSep = 1;
 
 struct Stack {
-  std::unique_ptr<xml::Node> root;
-  std::stack<xml::Node*> node_stack;
+  std::unique_ptr<xml::Element> root;
+  std::stack<xml::Element*> node_stack;
+  std::unique_ptr<xml::Element> pending_element;
   std::string pending_comment;
   std::unique_ptr<xml::Text> last_text_node;
 };
 
-/**
- * Extracts the namespace and name of an expanded element or attribute name.
- */
-static void SplitName(const char* name, std::string* out_ns,
-                      std::string* out_name) {
+// Extracts the namespace and name of an expanded element or attribute name.
+static void SplitName(const char* name, std::string* out_ns, std::string* out_name) {
   const char* p = name;
   while (*p != 0 && *p != kXmlNamespaceSep) {
     p++;
@@ -66,6 +65,7 @@ static void SplitName(const char* name, std::string* out_ns,
 static void FinishPendingText(Stack* stack) {
   if (stack->last_text_node != nullptr) {
     if (!stack->last_text_node->text.empty()) {
+      CHECK(!stack->node_stack.empty());
       stack->node_stack.top()->AppendChild(std::move(stack->last_text_node));
     } else {
       // Drop an empty text node.
@@ -74,48 +74,27 @@ static void FinishPendingText(Stack* stack) {
   }
 }
 
-static void AddToStack(Stack* stack, XML_Parser parser,
-                       std::unique_ptr<Node> node) {
-  node->line_number = XML_GetCurrentLineNumber(parser);
-  node->column_number = XML_GetCurrentColumnNumber(parser);
-
-  Node* this_node = node.get();
-  if (!stack->node_stack.empty()) {
-    stack->node_stack.top()->AppendChild(std::move(node));
-  } else {
-    stack->root = std::move(node);
-  }
-
-  if (!NodeCast<Text>(this_node)) {
-    stack->node_stack.push(this_node);
-  }
-}
-
-static void XMLCALL StartNamespaceHandler(void* user_data, const char* prefix,
-                                          const char* uri) {
+static void XMLCALL StartNamespaceHandler(void* user_data, const char* prefix, const char* uri) {
   XML_Parser parser = reinterpret_cast<XML_Parser>(user_data);
   Stack* stack = reinterpret_cast<Stack*>(XML_GetUserData(parser));
   FinishPendingText(stack);
 
-  std::unique_ptr<Namespace> ns = util::make_unique<Namespace>();
-  if (prefix) {
-    ns->namespace_prefix = prefix;
-  }
+  NamespaceDecl decl;
+  decl.line_number = XML_GetCurrentLineNumber(parser);
+  decl.column_number = XML_GetCurrentColumnNumber(parser);
+  decl.prefix = prefix ? prefix : "";
+  decl.uri = uri ? uri : "";
 
-  if (uri) {
-    ns->namespace_uri = uri;
+  if (stack->pending_element == nullptr) {
+    stack->pending_element = util::make_unique<Element>();
   }
-
-  AddToStack(stack, parser, std::move(ns));
+  stack->pending_element->namespace_decls.push_back(std::move(decl));
 }
 
-static void XMLCALL EndNamespaceHandler(void* user_data, const char* prefix) {
+static void XMLCALL EndNamespaceHandler(void* user_data, const char* /*prefix*/) {
   XML_Parser parser = reinterpret_cast<XML_Parser>(user_data);
   Stack* stack = reinterpret_cast<Stack*>(XML_GetUserData(parser));
   FinishPendingText(stack);
-
-  CHECK(!stack->node_stack.empty());
-  stack->node_stack.pop();
 }
 
 static bool less_attribute(const Attribute& lhs, const Attribute& rhs) {
@@ -123,28 +102,42 @@ static bool less_attribute(const Attribute& lhs, const Attribute& rhs) {
          std::tie(rhs.namespace_uri, rhs.name, rhs.value);
 }
 
-static void XMLCALL StartElementHandler(void* user_data, const char* name,
-                                        const char** attrs) {
+static void XMLCALL StartElementHandler(void* user_data, const char* name, const char** attrs) {
   XML_Parser parser = reinterpret_cast<XML_Parser>(user_data);
   Stack* stack = reinterpret_cast<Stack*>(XML_GetUserData(parser));
   FinishPendingText(stack);
 
-  std::unique_ptr<Element> el = util::make_unique<Element>();
+  std::unique_ptr<Element> el;
+  if (stack->pending_element != nullptr) {
+    el = std::move(stack->pending_element);
+  } else {
+    el = util::make_unique<Element>();
+  }
+
+  el->line_number = XML_GetCurrentLineNumber(parser);
+  el->column_number = XML_GetCurrentColumnNumber(parser);
+  el->comment = std::move(stack->pending_comment);
+
   SplitName(name, &el->namespace_uri, &el->name);
 
   while (*attrs) {
     Attribute attribute;
     SplitName(*attrs++, &attribute.namespace_uri, &attribute.name);
     attribute.value = *attrs++;
-
-    // Insert in sorted order.
-    auto iter = std::lower_bound(el->attributes.begin(), el->attributes.end(), attribute,
-                                 less_attribute);
-    el->attributes.insert(iter, std::move(attribute));
+    el->attributes.push_back(std::move(attribute));
   }
 
-  el->comment = std::move(stack->pending_comment);
-  AddToStack(stack, parser, std::move(el));
+  // Sort the attributes.
+  std::sort(el->attributes.begin(), el->attributes.end(), less_attribute);
+
+  // Add to the stack.
+  Element* this_el = el.get();
+  if (!stack->node_stack.empty()) {
+    stack->node_stack.top()->AppendChild(std::move(el));
+  } else {
+    stack->root = std::move(el);
+  }
+  stack->node_stack.push(this_el);
 }
 
 static void XMLCALL EndElementHandler(void* user_data, const char* name) {
@@ -189,40 +182,41 @@ static void XMLCALL CommentDataHandler(void* user_data, const char* comment) {
   stack->pending_comment += comment;
 }
 
-std::unique_ptr<XmlResource> Inflate(std::istream* in, IDiagnostics* diag, const Source& source) {
+std::unique_ptr<XmlResource> Inflate(InputStream* in, IDiagnostics* diag, const Source& source) {
   Stack stack;
 
-  XML_Parser parser = XML_ParserCreateNS(nullptr, kXmlNamespaceSep);
-  XML_SetUserData(parser, &stack);
-  XML_UseParserAsHandlerArg(parser);
-  XML_SetElementHandler(parser, StartElementHandler, EndElementHandler);
-  XML_SetNamespaceDeclHandler(parser, StartNamespaceHandler, EndNamespaceHandler);
-  XML_SetCharacterDataHandler(parser, CharacterDataHandler);
-  XML_SetCommentHandler(parser, CommentDataHandler);
+  std::unique_ptr<std::remove_pointer<XML_Parser>::type, decltype(XML_ParserFree)*> parser = {
+      XML_ParserCreateNS(nullptr, kXmlNamespaceSep), XML_ParserFree};
+  XML_SetUserData(parser.get(), &stack);
+  XML_UseParserAsHandlerArg(parser.get());
+  XML_SetElementHandler(parser.get(), StartElementHandler, EndElementHandler);
+  XML_SetNamespaceDeclHandler(parser.get(), StartNamespaceHandler, EndNamespaceHandler);
+  XML_SetCharacterDataHandler(parser.get(), CharacterDataHandler);
+  XML_SetCommentHandler(parser.get(), CommentDataHandler);
 
-  char buffer[1024];
-  while (!in->eof()) {
-    in->read(buffer, sizeof(buffer) / sizeof(buffer[0]));
-    if (in->bad() && !in->eof()) {
-      stack.root = {};
-      diag->Error(DiagMessage(source) << strerror(errno));
-      break;
-    }
-
-    if (XML_Parse(parser, buffer, in->gcount(), in->eof()) == XML_STATUS_ERROR) {
-      stack.root = {};
-      diag->Error(DiagMessage(source.WithLine(XML_GetCurrentLineNumber(parser)))
-                  << XML_ErrorString(XML_GetErrorCode(parser)));
-      break;
+  const char* buffer = nullptr;
+  size_t buffer_size = 0;
+  while (in->Next(reinterpret_cast<const void**>(&buffer), &buffer_size)) {
+    if (XML_Parse(parser.get(), buffer, buffer_size, false) == XML_STATUS_ERROR) {
+      diag->Error(DiagMessage(source.WithLine(XML_GetCurrentLineNumber(parser.get())))
+                  << XML_ErrorString(XML_GetErrorCode(parser.get())));
+      return {};
     }
   }
 
-  XML_ParserFree(parser);
-  if (stack.root) {
-    return util::make_unique<XmlResource>(ResourceFile{{}, {}, source}, StringPool{},
-                                          std::move(stack.root));
+  if (in->HadError()) {
+    diag->Error(DiagMessage(source) << in->GetError());
+    return {};
+  } else {
+    // Finish off the parsing.
+    if (XML_Parse(parser.get(), nullptr, 0u, true) == XML_STATUS_ERROR) {
+      diag->Error(DiagMessage(source.WithLine(XML_GetCurrentLineNumber(parser.get())))
+                  << XML_ErrorString(XML_GetErrorCode(parser.get())));
+      return {};
+    }
   }
-  return {};
+  return util::make_unique<XmlResource>(ResourceFile{{}, {}, source}, StringPool{},
+                                        std::move(stack.root));
 }
 
 static void CopyAttributes(Element* el, android::ResXMLParser* parser, StringPool* out_pool) {
@@ -261,13 +255,13 @@ static void CopyAttributes(Element* el, android::ResXMLParser* parser, StringPoo
 std::unique_ptr<XmlResource> Inflate(const void* data, size_t data_len, IDiagnostics* diag,
                                      const Source& source) {
   // We import the android namespace because on Windows NO_ERROR is a macro, not
-  // an enum, which
-  // causes errors when qualifying it with android::
+  // an enum, which causes errors when qualifying it with android::
   using namespace android;
 
   StringPool string_pool;
-  std::unique_ptr<Node> root;
-  std::stack<Node*> node_stack;
+  std::unique_ptr<Element> root;
+  std::stack<Element*> node_stack;
+  std::unique_ptr<Element> pending_element;
 
   ResXMLTree tree;
   if (tree.setTo(data, data_len) != NO_ERROR) {
@@ -275,57 +269,76 @@ std::unique_ptr<XmlResource> Inflate(const void* data, size_t data_len, IDiagnos
   }
 
   ResXMLParser::event_code_t code;
-  while ((code = tree.next()) != ResXMLParser::BAD_DOCUMENT &&
-         code != ResXMLParser::END_DOCUMENT) {
+  while ((code = tree.next()) != ResXMLParser::BAD_DOCUMENT && code != ResXMLParser::END_DOCUMENT) {
     std::unique_ptr<Node> new_node;
     switch (code) {
       case ResXMLParser::START_NAMESPACE: {
-        std::unique_ptr<Namespace> node = util::make_unique<Namespace>();
+        NamespaceDecl decl;
         size_t len;
         const char16_t* str16 = tree.getNamespacePrefix(&len);
         if (str16) {
-          node->namespace_prefix = util::Utf16ToUtf8(StringPiece16(str16, len));
+          decl.prefix = util::Utf16ToUtf8(StringPiece16(str16, len));
         }
 
         str16 = tree.getNamespaceUri(&len);
         if (str16) {
-          node->namespace_uri = util::Utf16ToUtf8(StringPiece16(str16, len));
+          decl.uri = util::Utf16ToUtf8(StringPiece16(str16, len));
+        }
+
+        if (pending_element == nullptr) {
+          pending_element = util::make_unique<Element>();
         }
-        new_node = std::move(node);
         break;
       }
 
       case ResXMLParser::START_TAG: {
-        std::unique_ptr<Element> node = util::make_unique<Element>();
+        std::unique_ptr<Element> el;
+        if (pending_element != nullptr) {
+          el = std::move(pending_element);
+        } else {
+          el = util::make_unique<Element>();
+          ;
+        }
+
         size_t len;
         const char16_t* str16 = tree.getElementNamespace(&len);
         if (str16) {
-          node->namespace_uri = util::Utf16ToUtf8(StringPiece16(str16, len));
+          el->namespace_uri = util::Utf16ToUtf8(StringPiece16(str16, len));
         }
 
         str16 = tree.getElementName(&len);
         if (str16) {
-          node->name = util::Utf16ToUtf8(StringPiece16(str16, len));
+          el->name = util::Utf16ToUtf8(StringPiece16(str16, len));
         }
 
-        CopyAttributes(node.get(), &tree, &string_pool);
+        Element* this_el = el.get();
+        CopyAttributes(el.get(), &tree, &string_pool);
 
-        new_node = std::move(node);
+        if (!node_stack.empty()) {
+          node_stack.top()->AppendChild(std::move(el));
+        } else {
+          root = std::move(el);
+        }
+        node_stack.push(this_el);
         break;
       }
 
       case ResXMLParser::TEXT: {
-        std::unique_ptr<Text> node = util::make_unique<Text>();
+        std::unique_ptr<Text> text = util::make_unique<Text>();
+        text->line_number = tree.getLineNumber();
         size_t len;
         const char16_t* str16 = tree.getText(&len);
         if (str16) {
-          node->text = util::Utf16ToUtf8(StringPiece16(str16, len));
+          text->text = util::Utf16ToUtf8(StringPiece16(str16, len));
         }
-        new_node = std::move(node);
+        CHECK(!node_stack.empty());
+        node_stack.top()->AppendChild(std::move(text));
         break;
       }
 
       case ResXMLParser::END_NAMESPACE:
+        break;
+
       case ResXMLParser::END_TAG:
         CHECK(!node_stack.empty());
         node_stack.pop();
@@ -335,74 +348,32 @@ std::unique_ptr<XmlResource> Inflate(const void* data, size_t data_len, IDiagnos
         LOG(FATAL) << "unhandled XML chunk type";
         break;
     }
-
-    if (new_node) {
-      new_node->line_number = tree.getLineNumber();
-
-      Node* this_node = new_node.get();
-      if (!root) {
-        CHECK(node_stack.empty()) << "node stack should be empty";
-        root = std::move(new_node);
-      } else {
-        CHECK(!node_stack.empty()) << "node stack should not be empty";
-        node_stack.top()->AppendChild(std::move(new_node));
-      }
-
-      if (!NodeCast<Text>(this_node)) {
-        node_stack.push(this_node);
-      }
-    }
   }
   return util::make_unique<XmlResource>(ResourceFile{}, std::move(string_pool), std::move(root));
 }
 
-std::unique_ptr<Node> Namespace::Clone(const ElementCloneFunc& el_cloner) {
-  auto ns = util::make_unique<Namespace>();
-  ns->comment = comment;
-  ns->line_number = line_number;
-  ns->column_number = column_number;
-  ns->namespace_prefix = namespace_prefix;
-  ns->namespace_uri = namespace_uri;
-  ns->children.reserve(children.size());
-  for (const std::unique_ptr<xml::Node>& child : children) {
-    ns->AppendChild(child->Clone(el_cloner));
-  }
-  return std::move(ns);
-}
-
-Element* FindRootElement(XmlResource* doc) {
-  return FindRootElement(doc->root.get());
-}
-
 Element* FindRootElement(Node* node) {
-  if (!node) {
+  if (node == nullptr) {
     return nullptr;
   }
 
-  Element* el = nullptr;
-  while ((el = NodeCast<Element>(node)) == nullptr) {
-    if (node->children.empty()) {
-      return nullptr;
-    }
-    // We are looking for the first element, and namespaces can only have one
-    // child.
-    node = node->children.front().get();
+  while (node->parent != nullptr) {
+    node = node->parent;
   }
-  return el;
+  return NodeCast<Element>(node);
 }
 
-void Node::AppendChild(std::unique_ptr<Node> child) {
+void Element::AppendChild(std::unique_ptr<Node> child) {
   child->parent = this;
   children.push_back(std::move(child));
 }
 
-void Node::InsertChild(size_t index, std::unique_ptr<Node> child) {
+void Element::InsertChild(size_t index, std::unique_ptr<Node> child) {
   child->parent = this;
   children.insert(children.begin() + index, std::move(child));
 }
 
-Attribute* Element::FindAttribute(const StringPiece& ns,
-                                  const StringPiece& name) {
+Attribute* Element::FindAttribute(const StringPiece& ns, const StringPiece& name) {
   for (auto& attr : attributes) {
     if (ns == attr.namespace_uri && name == attr.name) {
       return &attr;
@@ -424,21 +395,11 @@ Element* Element::FindChild(const StringPiece& ns, const StringPiece& name) {
   return FindChildWithAttribute(ns, name, {}, {}, {});
 }
 
-Element* Element::FindChildWithAttribute(const StringPiece& ns,
-                                         const StringPiece& name,
-                                         const StringPiece& attr_ns,
-                                         const StringPiece& attr_name,
+Element* Element::FindChildWithAttribute(const StringPiece& ns, const StringPiece& name,
+                                         const StringPiece& attr_ns, const StringPiece& attr_name,
                                          const StringPiece& attr_value) {
-  for (auto& child_node : children) {
-    Node* child = child_node.get();
-    while (NodeCast<Namespace>(child)) {
-      if (child->children.empty()) {
-        break;
-      }
-      child = child->children[0].get();
-    }
-
-    if (Element* el = NodeCast<Element>(child)) {
+  for (auto& child : children) {
+    if (Element* el = NodeCast<Element>(child.get())) {
       if (ns == el->namespace_uri && name == el->name) {
         if (attr_ns.empty() && attr_name.empty()) {
           return el;
@@ -457,23 +418,16 @@ Element* Element::FindChildWithAttribute(const StringPiece& ns,
 std::vector<Element*> Element::GetChildElements() {
   std::vector<Element*> elements;
   for (auto& child_node : children) {
-    Node* child = child_node.get();
-    while (NodeCast<Namespace>(child)) {
-      if (child->children.empty()) {
-        break;
-      }
-      child = child->children[0].get();
-    }
-
-    if (Element* el = NodeCast<Element>(child)) {
-      elements.push_back(el);
+    if (Element* child = NodeCast<Element>(child_node.get())) {
+      elements.push_back(child);
     }
   }
   return elements;
 }
 
-std::unique_ptr<Node> Element::Clone(const ElementCloneFunc& el_cloner) {
+std::unique_ptr<Node> Element::Clone(const ElementCloneFunc& el_cloner) const {
   auto el = util::make_unique<Element>();
+  el->namespace_decls = namespace_decls;
   el->comment = comment;
   el->line_number = line_number;
   el->column_number = column_number;
@@ -488,7 +442,17 @@ std::unique_ptr<Node> Element::Clone(const ElementCloneFunc& el_cloner) {
   return std::move(el);
 }
 
-std::unique_ptr<Node> Text::Clone(const ElementCloneFunc&) {
+std::unique_ptr<Element> Element::CloneElement(const ElementCloneFunc& el_cloner) const {
+  return std::unique_ptr<Element>(static_cast<Element*>(Clone(el_cloner).release()));
+}
+
+void Element::Accept(Visitor* visitor) {
+  visitor->BeforeVisitElement(this);
+  visitor->Visit(this);
+  visitor->AfterVisitElement(this);
+}
+
+std::unique_ptr<Node> Text::Clone(const ElementCloneFunc&) const {
   auto t = util::make_unique<Text>();
   t->comment = comment;
   t->line_number = line_number;
@@ -497,21 +461,22 @@ std::unique_ptr<Node> Text::Clone(const ElementCloneFunc&) {
   return std::move(t);
 }
 
-void PackageAwareVisitor::Visit(Namespace* ns) {
-  bool added = false;
-  if (Maybe<ExtractedPackage> maybe_package =
-          ExtractPackageFromNamespace(ns->namespace_uri)) {
-    ExtractedPackage& package = maybe_package.value();
-    package_decls_.push_back(
-        PackageDecl{ns->namespace_prefix, std::move(package)});
-    added = true;
-  }
+void Text::Accept(Visitor* visitor) {
+  visitor->Visit(this);
+}
 
-  Visitor::Visit(ns);
-
-  if (added) {
-    package_decls_.pop_back();
+void PackageAwareVisitor::BeforeVisitElement(Element* el) {
+  std::vector<PackageDecl> decls;
+  for (const NamespaceDecl& decl : el->namespace_decls) {
+    if (Maybe<ExtractedPackage> maybe_package = ExtractPackageFromNamespace(decl.uri)) {
+      decls.push_back(PackageDecl{decl.prefix, std::move(maybe_package.value())});
+    }
   }
+  package_decls_.push_back(std::move(decls));
+}
+
+void PackageAwareVisitor::AfterVisitElement(Element* el) {
+  package_decls_.pop_back();
 }
 
 Maybe<ExtractedPackage> PackageAwareVisitor::TransformPackageAlias(
@@ -522,11 +487,16 @@ Maybe<ExtractedPackage> PackageAwareVisitor::TransformPackageAlias(
 
   const auto rend = package_decls_.rend();
   for (auto iter = package_decls_.rbegin(); iter != rend; ++iter) {
-    if (alias == iter->prefix) {
-      if (iter->package.package.empty()) {
-        return ExtractedPackage{local_package.to_string(), iter->package.private_namespace};
+    const std::vector<PackageDecl>& decls = *iter;
+    const auto rend2 = decls.rend();
+    for (auto iter2 = decls.rbegin(); iter2 != rend2; ++iter2) {
+      const PackageDecl& decl = *iter2;
+      if (alias == decl.prefix) {
+        if (decl.package.package.empty()) {
+          return ExtractedPackage{local_package.to_string(), decl.package.private_namespace};
+        }
+        return decl.package;
       }
-      return iter->package;
     }
   }
   return {};
diff --git a/tools/aapt2/xml/XmlDom.h b/tools/aapt2/xml/XmlDom.h
index 2dc99d6931484..1542243816266 100644
--- a/tools/aapt2/xml/XmlDom.h
+++ b/tools/aapt2/xml/XmlDom.h
@@ -17,7 +17,6 @@
 #ifndef AAPT_XML_DOM_H
 #define AAPT_XML_DOM_H
 
-#include <istream>
 #include <memory>
 #include <string>
 #include <vector>
@@ -27,58 +26,40 @@
 #include "Diagnostics.h"
 #include "Resource.h"
 #include "ResourceValues.h"
+#include "io/Io.h"
 #include "util/Util.h"
 #include "xml/XmlUtil.h"
 
 namespace aapt {
 namespace xml {
 
-class RawVisitor;
-
 class Element;
+class Visitor;
 
-/**
- * Base class for all XML nodes.
- */
+// Base class for all XML nodes.
 class Node {
  public:
-  Node* parent = nullptr;
-  size_t line_number = 0;
-  size_t column_number = 0;
-  std::string comment;
-  std::vector<std::unique_ptr<Node>> children;
-
   virtual ~Node() = default;
 
-  void AppendChild(std::unique_ptr<Node> child);
-  void InsertChild(size_t index, std::unique_ptr<Node> child);
-  virtual void Accept(RawVisitor* visitor) = 0;
+  Element* parent = nullptr;
+  size_t line_number = 0u;
+  size_t column_number = 0u;
+  std::string comment;
+
+  virtual void Accept(Visitor* visitor) = 0;
 
   using ElementCloneFunc = std::function<void(const Element&, Element*)>;
 
   // Clones the Node subtree, using the given function to decide how to clone an Element.
-  virtual std::unique_ptr<Node> Clone(const ElementCloneFunc& el_cloner) = 0;
+  virtual std::unique_ptr<Node> Clone(const ElementCloneFunc& el_cloner) const = 0;
 };
 
-/**
- * Base class that implements the visitor methods for a
- * subclass of Node.
- */
-template <typename Derived>
-class BaseNode : public Node {
- public:
-  virtual void Accept(RawVisitor* visitor) override;
-};
-
-/**
- * A Namespace XML node. Can only have one child.
- */
-class Namespace : public BaseNode<Namespace> {
- public:
-  std::string namespace_prefix;
-  std::string namespace_uri;
-
-  std::unique_ptr<Node> Clone(const ElementCloneFunc& el_cloner) override;
+// A namespace declaration (xmlns:prefix="uri").
+struct NamespaceDecl {
+  std::string prefix;
+  std::string uri;
+  size_t line_number = 0u;
+  size_t column_number = 0u;
 };
 
 struct AaptAttribute {
@@ -90,9 +71,7 @@ struct AaptAttribute {
   Maybe<ResourceId> id;
 };
 
-/**
- * An XML attribute.
- */
+// An XML attribute.
 struct Attribute {
   std::string namespace_uri;
   std::string name;
@@ -102,41 +81,50 @@ struct Attribute {
   std::unique_ptr<Item> compiled_value;
 };
 
-/**
- * An Element XML node.
- */
-class Element : public BaseNode<Element> {
+// An Element XML node.
+class Element : public Node {
  public:
+  // Ordered namespace prefix declarations.
+  std::vector<NamespaceDecl> namespace_decls;
+
   std::string namespace_uri;
   std::string name;
   std::vector<Attribute> attributes;
+  std::vector<std::unique_ptr<Node>> children;
+
+  void AppendChild(std::unique_ptr<Node> child);
+  void InsertChild(size_t index, std::unique_ptr<Node> child);
 
   Attribute* FindAttribute(const android::StringPiece& ns, const android::StringPiece& name);
   const Attribute* FindAttribute(const android::StringPiece& ns,
                                  const android::StringPiece& name) const;
-  xml::Element* FindChild(const android::StringPiece& ns, const android::StringPiece& name);
-  xml::Element* FindChildWithAttribute(const android::StringPiece& ns,
-                                       const android::StringPiece& name,
-                                       const android::StringPiece& attr_ns,
-                                       const android::StringPiece& attr_name,
-                                       const android::StringPiece& attr_value);
-  std::vector<xml::Element*> GetChildElements();
-  std::unique_ptr<Node> Clone(const ElementCloneFunc& el_cloner) override;
+  Element* FindChild(const android::StringPiece& ns, const android::StringPiece& name);
+  Element* FindChildWithAttribute(const android::StringPiece& ns, const android::StringPiece& name,
+                                  const android::StringPiece& attr_ns,
+                                  const android::StringPiece& attr_name,
+                                  const android::StringPiece& attr_value);
+  std::vector<Element*> GetChildElements();
+
+  // Due to overriding of subtypes not working with unique_ptr, define a convenience Clone method
+  // that knows cloning an element returns an element.
+  std::unique_ptr<Element> CloneElement(const ElementCloneFunc& el_cloner) const;
+
+  std::unique_ptr<Node> Clone(const ElementCloneFunc& el_cloner) const override;
+
+  void Accept(Visitor* visitor) override;
 };
 
-/**
- * A Text (CDATA) XML node. Can not have any children.
- */
-class Text : public BaseNode<Text> {
+// A Text (CDATA) XML node. Can not have any children.
+class Text : public Node {
  public:
   std::string text;
 
-  std::unique_ptr<Node> Clone(const ElementCloneFunc& el_cloner) override;
+  std::unique_ptr<Node> Clone(const ElementCloneFunc& el_cloner) const override;
+
+  void Accept(Visitor* visitor) override;
 };
 
-/**
- * An XML resource with a source, name, and XML tree.
- */
+// An XML resource with a source, name, and XML tree.
 class XmlResource {
  public:
   ResourceFile file;
@@ -146,99 +134,121 @@ class XmlResource {
   // is destroyed.
   StringPool string_pool;
 
-  std::unique_ptr<xml::Node> root;
+  std::unique_ptr<xml::Element> root;
 };
 
-/**
- * Inflates an XML DOM from a text stream, logging errors to the logger.
- * Returns the root node on success, or nullptr on failure.
- */
-std::unique_ptr<XmlResource> Inflate(std::istream* in, IDiagnostics* diag, const Source& source);
+// Inflates an XML DOM from an InputStream, logging errors to the logger.
+// Returns the root node on success, or nullptr on failure.
+std::unique_ptr<XmlResource> Inflate(io::InputStream* in, IDiagnostics* diag, const Source& source);
 
-/**
- * Inflates an XML DOM from a binary ResXMLTree, logging errors to the logger.
- * Returns the root node on success, or nullptr on failure.
- */
+// Inflates an XML DOM from a binary ResXMLTree, logging errors to the logger.
+// Returns the root node on success, or nullptr on failure.
 std::unique_ptr<XmlResource> Inflate(const void* data, size_t data_len, IDiagnostics* diag,
                                      const Source& source);
 
-Element* FindRootElement(XmlResource* doc);
 Element* FindRootElement(Node* node);
 
-/**
- * A visitor interface for the different XML Node subtypes. This will not
- * traverse into
- * children. Use Visitor for that.
- */
-class RawVisitor {
+// Visitor whose default implementation visits the children nodes of any node.
+class Visitor {
  public:
-  virtual ~RawVisitor() = default;
+  virtual ~Visitor() = default;
 
-  virtual void Visit(Namespace* node) {}
-  virtual void Visit(Element* node) {}
-  virtual void Visit(Text* text) {}
-};
+  virtual void Visit(Element* el) {
+    VisitChildren(el);
+  }
 
-/**
- * Visitor whose default implementation visits the children nodes of any node.
- */
-class Visitor : public RawVisitor {
- public:
-  using RawVisitor::Visit;
+  virtual void Visit(Text* text) {
+  }
 
-  void Visit(Namespace* node) override { VisitChildren(node); }
+ protected:
+  Visitor() = default;
 
-  void Visit(Element* node) override { VisitChildren(node); }
-
-  void Visit(Text* text) override { VisitChildren(text); }
-
-  void VisitChildren(Node* node) {
-    for (auto& child : node->children) {
+  void VisitChildren(Element* el) {
+    for (auto& child : el->children) {
       child->Accept(this);
     }
   }
+
+  virtual void BeforeVisitElement(Element* el) {
+  }
+  virtual void AfterVisitElement(Element* el) {
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(Visitor);
+
+  friend class Element;
 };
 
-/**
- * An XML DOM visitor that will record the package name for a namespace prefix.
- */
+// An XML DOM visitor that will record the package name for a namespace prefix.
 class PackageAwareVisitor : public Visitor, public IPackageDeclStack {
  public:
   using Visitor::Visit;
 
-  void Visit(Namespace* ns) override;
   Maybe<ExtractedPackage> TransformPackageAlias(
       const android::StringPiece& alias, const android::StringPiece& local_package) const override;
 
+ protected:
+  PackageAwareVisitor() = default;
+
+  void BeforeVisitElement(Element* el) override;
+  void AfterVisitElement(Element* el) override;
+
  private:
+  DISALLOW_COPY_AND_ASSIGN(PackageAwareVisitor);
+
   struct PackageDecl {
     std::string prefix;
     ExtractedPackage package;
   };
 
-  std::vector<PackageDecl> package_decls_;
+  std::vector<std::vector<PackageDecl>> package_decls_;
 };
 
-// Implementations
+namespace internal {
 
-template <typename Derived>
-void BaseNode<Derived>::Accept(RawVisitor* visitor) {
-  visitor->Visit(static_cast<Derived*>(this));
-}
+// Base class that overrides the default behaviour and does not descend into child nodes.
+class NodeCastBase : public Visitor {
+ public:
+  void Visit(Element* el) override {
+  }
+  void Visit(Text* el) override {
+  }
+
+ protected:
+  NodeCastBase() = default;
+
+  void BeforeVisitElement(Element* el) override {
+  }
+  void AfterVisitElement(Element* el) override {
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NodeCastBase);
+};
 
 template <typename T>
-class NodeCastImpl : public RawVisitor {
+class NodeCastImpl : public NodeCastBase {
  public:
-  using RawVisitor::Visit;
+  using NodeCastBase::Visit;
+
+  NodeCastImpl() = default;
 
   T* value = nullptr;
 
-  void Visit(T* v) override { value = v; }
+  void Visit(T* v) override {
+    value = v;
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NodeCastImpl);
 };
 
+}  // namespace internal
+
 template <typename T>
 T* NodeCast(Node* node) {
-  NodeCastImpl<T> visitor;
+  internal::NodeCastImpl<T> visitor;
   node->Accept(&visitor);
   return visitor.value;
 }
diff --git a/tools/aapt2/xml/XmlDom_test.cpp b/tools/aapt2/xml/XmlDom_test.cpp
index f0122e8c617a3..6ed2d616f7828 100644
--- a/tools/aapt2/xml/XmlDom_test.cpp
+++ b/tools/aapt2/xml/XmlDom_test.cpp
@@ -16,23 +16,22 @@
 
 #include "xml/XmlDom.h"
 
-#include <sstream>
 #include <string>
 
+#include "io/StringInputStream.h"
 #include "test/Test.h"
 
+using ::aapt::io::StringInputStream;
 using ::testing::Eq;
 using ::testing::NotNull;
 using ::testing::SizeIs;
+using ::testing::StrEq;
 
 namespace aapt {
-
-constexpr const char* kXmlPreamble =
-    "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
+namespace xml {
 
 TEST(XmlDomTest, Inflate) {
-  std::stringstream in(kXmlPreamble);
-  in << R"(
+  std::string input = R"(<?xml version="1.0" encoding="utf-8"?>
       <Layout xmlns:android="http://schemas.android.com/apk/res/android"
           android:layout_width="match_parent"
           android:layout_height="wrap_content">
@@ -41,26 +40,25 @@ TEST(XmlDomTest, Inflate) {
             android:layout_height="wrap_content" />
       </Layout>)";
 
-  const Source source("test.xml");
   StdErrDiagnostics diag;
-  std::unique_ptr<xml::XmlResource> doc = xml::Inflate(&in, &diag, source);
+  StringInputStream in(input);
+  std::unique_ptr<XmlResource> doc = Inflate(&in, &diag, Source("test.xml"));
   ASSERT_THAT(doc, NotNull());
 
-  xml::Namespace* ns = xml::NodeCast<xml::Namespace>(doc->root.get());
-  ASSERT_THAT(ns, NotNull());
-  EXPECT_THAT(ns->namespace_uri, Eq(xml::kSchemaAndroid));
-  EXPECT_THAT(ns->namespace_prefix, Eq("android"));
+  Element* el = doc->root.get();
+  EXPECT_THAT(el->namespace_decls, SizeIs(1u));
+  EXPECT_THAT(el->namespace_decls[0].uri, StrEq(xml::kSchemaAndroid));
+  EXPECT_THAT(el->namespace_decls[0].prefix, StrEq("android"));
 }
 
 // Escaping is handled after parsing of the values for resource-specific values.
 TEST(XmlDomTest, ForwardEscapes) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"(
+  std::unique_ptr<XmlResource> doc = test::BuildXmlDom(R"(
       <element value="\?hello" pattern="\\d{5}">\\d{5}</element>)");
 
-  xml::Element* el = xml::FindRootElement(doc.get());
-  ASSERT_THAT(el, NotNull());
+  Element* el = doc->root.get();
 
-  xml::Attribute* attr = el->FindAttribute({}, "pattern");
+  Attribute* attr = el->FindAttribute({}, "pattern");
   ASSERT_THAT(attr, NotNull());
   EXPECT_THAT(attr->value, Eq("\\\\d{5}"));
 
@@ -70,21 +68,54 @@ TEST(XmlDomTest, ForwardEscapes) {
 
   ASSERT_THAT(el->children, SizeIs(1u));
 
-  xml::Text* text = xml::NodeCast<xml::Text>(el->children[0].get());
+  Text* text = xml::NodeCast<xml::Text>(el->children[0].get());
   ASSERT_THAT(text, NotNull());
   EXPECT_THAT(text->text, Eq("\\\\d{5}"));
 }
 
 TEST(XmlDomTest, XmlEscapeSequencesAreParsed) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"(<element value="&quot;" />)");
-
-  xml::Element* el = xml::FindRootElement(doc.get());
-  ASSERT_THAT(el, NotNull());
-
-  xml::Attribute* attr = el->FindAttribute({}, "value");
+  std::unique_ptr<XmlResource> doc = test::BuildXmlDom(R"(<element value="&quot;" />)");
+  Attribute* attr = doc->root->FindAttribute({}, "value");
   ASSERT_THAT(attr, NotNull());
-
   EXPECT_THAT(attr->value, Eq("\""));
 }
 
+class TestVisitor : public PackageAwareVisitor {
+ public:
+  using PackageAwareVisitor::Visit;
+
+  void Visit(Element* el) override {
+    if (el->name == "View1") {
+      EXPECT_THAT(TransformPackageAlias("one", "local"),
+                  Eq(make_value(ExtractedPackage{"com.one", false})));
+    } else if (el->name == "View2") {
+      EXPECT_THAT(TransformPackageAlias("one", "local"),
+                  Eq(make_value(ExtractedPackage{"com.one", false})));
+      EXPECT_THAT(TransformPackageAlias("two", "local"),
+                  Eq(make_value(ExtractedPackage{"com.two", false})));
+    } else if (el->name == "View3") {
+      EXPECT_THAT(TransformPackageAlias("one", "local"),
+                  Eq(make_value(ExtractedPackage{"com.one", false})));
+      EXPECT_THAT(TransformPackageAlias("two", "local"),
+                  Eq(make_value(ExtractedPackage{"com.two", false})));
+      EXPECT_THAT(TransformPackageAlias("three", "local"),
+                  Eq(make_value(ExtractedPackage{"com.three", false})));
+    }
+  }
+};
+
+TEST(XmlDomTest, PackageAwareXmlVisitor) {
+  std::unique_ptr<XmlResource> doc = test::BuildXmlDom(R"(
+      <View1 xmlns:one="http://schemas.android.com/apk/res/com.one">
+        <View2 xmlns:two="http://schemas.android.com/apk/res/com.two">
+          <View3 xmlns:three="http://schemas.android.com/apk/res/com.three" />
+        </View2>
+      </View1>)");
+
+  Debug::DumpXml(doc.get());
+  TestVisitor visitor;
+  doc->root->Accept(&visitor);
+}
+
+}  // namespace xml
 }  // namespace aapt
diff --git a/tools/aapt2/xml/XmlPullParser.cpp b/tools/aapt2/xml/XmlPullParser.cpp
index c2a9c8283a6d2..30bdc507303be 100644
--- a/tools/aapt2/xml/XmlPullParser.cpp
+++ b/tools/aapt2/xml/XmlPullParser.cpp
@@ -22,14 +22,15 @@
 #include "xml/XmlPullParser.h"
 #include "xml/XmlUtil.h"
 
-using android::StringPiece;
+using ::aapt::io::InputStream;
+using ::android::StringPiece;
 
 namespace aapt {
 namespace xml {
 
 constexpr char kXmlNamespaceSep = 1;
 
-XmlPullParser::XmlPullParser(std::istream& in) : in_(in), empty_(), depth_(0) {
+XmlPullParser::XmlPullParser(InputStream* in) : in_(in), empty_(), depth_(0) {
   parser_ = XML_ParserCreateNS(nullptr, kXmlNamespaceSep);
   XML_SetUserData(parser_, this);
   XML_SetElementHandler(parser_, StartElementHandler, EndElementHandler);
@@ -40,30 +41,35 @@ XmlPullParser::XmlPullParser(std::istream& in) : in_(in), empty_(), depth_(0) {
   event_queue_.push(EventData{Event::kStartDocument, 0, depth_++});
 }
 
-XmlPullParser::~XmlPullParser() { XML_ParserFree(parser_); }
+XmlPullParser::~XmlPullParser() {
+  XML_ParserFree(parser_);
+}
 
 XmlPullParser::Event XmlPullParser::Next() {
   const Event currentEvent = event();
-  if (currentEvent == Event::kBadDocument ||
-      currentEvent == Event::kEndDocument) {
+  if (currentEvent == Event::kBadDocument || currentEvent == Event::kEndDocument) {
     return currentEvent;
   }
 
   event_queue_.pop();
   while (event_queue_.empty()) {
-    in_.read(buffer_, sizeof(buffer_) / sizeof(*buffer_));
+    const char* buffer = nullptr;
+    size_t buffer_size = 0;
+    bool done = false;
+    if (!in_->Next(reinterpret_cast<const void**>(&buffer), &buffer_size)) {
+      if (in_->HadError()) {
+        error_ = in_->GetError();
+        event_queue_.push(EventData{Event::kBadDocument});
+        break;
+      }
 
-    const bool done = in_.eof();
-    if (in_.bad() && !done) {
-      error_ = strerror(errno);
-      event_queue_.push(EventData{Event::kBadDocument});
-      continue;
+      done = true;
     }
 
-    if (XML_Parse(parser_, buffer_, in_.gcount(), done) == XML_STATUS_ERROR) {
+    if (XML_Parse(parser_, buffer, buffer_size, done) == XML_STATUS_ERROR) {
       error_ = XML_ErrorString(XML_GetErrorCode(parser_));
       event_queue_.push(EventData{Event::kBadDocument});
-      continue;
+      break;
     }
 
     if (done) {
diff --git a/tools/aapt2/xml/XmlPullParser.h b/tools/aapt2/xml/XmlPullParser.h
index cdeeefd139764..a00caa139061b 100644
--- a/tools/aapt2/xml/XmlPullParser.h
+++ b/tools/aapt2/xml/XmlPullParser.h
@@ -31,6 +31,7 @@
 #include "androidfw/StringPiece.h"
 
 #include "Resource.h"
+#include "io/Io.h"
 #include "process/IResourceTableConsumer.h"
 #include "util/Maybe.h"
 #include "xml/XmlUtil.h"
@@ -64,7 +65,7 @@ class XmlPullParser : public IPackageDeclStack {
   static bool SkipCurrentElement(XmlPullParser* parser);
   static bool IsGoodEvent(Event event);
 
-  explicit XmlPullParser(std::istream& in);
+  explicit XmlPullParser(io::InputStream* in);
   ~XmlPullParser();
 
   /**
@@ -169,9 +170,8 @@ class XmlPullParser : public IPackageDeclStack {
     std::vector<Attribute> attributes;
   };
 
-  std::istream& in_;
+  io::InputStream* in_;
   XML_Parser parser_;
-  char buffer_[16384];
   std::queue<EventData> event_queue_;
   std::string error_;
   const std::string empty_;
@@ -228,18 +228,15 @@ inline ::std::ostream& operator<<(::std::ostream& out,
   return out;
 }
 
-inline bool XmlPullParser::NextChildNode(XmlPullParser* parser,
-                                         size_t start_depth) {
+inline bool XmlPullParser::NextChildNode(XmlPullParser* parser, size_t start_depth) {
   Event event;
 
   // First get back to the start depth.
-  while (IsGoodEvent(event = parser->Next()) &&
-         parser->depth() > start_depth + 1) {
+  while (IsGoodEvent(event = parser->Next()) && parser->depth() > start_depth + 1) {
   }
 
   // Now look for the first good node.
-  while ((event != Event::kEndElement || parser->depth() > start_depth) &&
-         IsGoodEvent(event)) {
+  while ((event != Event::kEndElement || parser->depth() > start_depth) && IsGoodEvent(event)) {
     switch (event) {
       case Event::kText:
       case Event::kComment:
diff --git a/tools/aapt2/xml/XmlPullParser_test.cpp b/tools/aapt2/xml/XmlPullParser_test.cpp
index 1cce4850cac56..681d9d48173f0 100644
--- a/tools/aapt2/xml/XmlPullParser_test.cpp
+++ b/tools/aapt2/xml/XmlPullParser_test.cpp
@@ -16,21 +16,22 @@
 
 #include "xml/XmlPullParser.h"
 
-#include <sstream>
-
 #include "androidfw/StringPiece.h"
 
+#include "io/StringInputStream.h"
 #include "test/Test.h"
 
-using android::StringPiece;
+using ::aapt::io::StringInputStream;
+using ::android::StringPiece;
 
 namespace aapt {
 
 TEST(XmlPullParserTest, NextChildNodeTraversesCorrectly) {
-  std::stringstream str;
-  str << "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n"
-         "<a><b><c xmlns:a=\"http://schema.org\"><d/></c><e/></b></a>";
-  xml::XmlPullParser parser(str);
+  std::string str =
+      R"(<?xml version="1.0" encoding="utf-8"?>
+         <a><b><c xmlns:a="http://schema.org"><d/></c><e/></b></a>)";
+  StringInputStream input(str);
+  xml::XmlPullParser parser(&input);
 
   const size_t depth_outer = parser.depth();
   ASSERT_TRUE(xml::XmlPullParser::NextChildNode(&parser, depth_outer));
diff --git a/tools/aapt2/xml/XmlUtil.h b/tools/aapt2/xml/XmlUtil.h
index 1650ac2124ac4..866b6dcd7a880 100644
--- a/tools/aapt2/xml/XmlUtil.h
+++ b/tools/aapt2/xml/XmlUtil.h
@@ -26,79 +26,56 @@ namespace aapt {
 namespace xml {
 
 constexpr const char* kSchemaAuto = "http://schemas.android.com/apk/res-auto";
-constexpr const char* kSchemaPublicPrefix =
-    "http://schemas.android.com/apk/res/";
-constexpr const char* kSchemaPrivatePrefix =
-    "http://schemas.android.com/apk/prv/res/";
-constexpr const char* kSchemaAndroid =
-    "http://schemas.android.com/apk/res/android";
+constexpr const char* kSchemaPublicPrefix = "http://schemas.android.com/apk/res/";
+constexpr const char* kSchemaPrivatePrefix = "http://schemas.android.com/apk/prv/res/";
+constexpr const char* kSchemaAndroid = "http://schemas.android.com/apk/res/android";
 constexpr const char* kSchemaTools = "http://schemas.android.com/tools";
 constexpr const char* kSchemaAapt = "http://schemas.android.com/aapt";
 
-/**
- * Result of extracting a package name from a namespace URI declaration.
- */
+// Result of extracting a package name from a namespace URI declaration.
 struct ExtractedPackage {
-  /**
-   * The name of the package. This can be the empty string, which means that the
-   * package
-   * should be assumed to be the package being compiled.
-   */
+  // The name of the package. This can be the empty string, which means that the package
+  // should be assumed to be the package being compiled.
   std::string package;
 
-  /**
-   * True if the package's private namespace was declared. This means that
-   * private resources
-   * are made visible.
-   */
+  // True if the package's private namespace was declared. This means that private resources
+  // are made visible.
   bool private_namespace;
+
+  friend inline bool operator==(const ExtractedPackage& a, const ExtractedPackage& b) {
+    return a.package == b.package && a.private_namespace == b.private_namespace;
+  }
 };
 
-/**
- * Returns an ExtractedPackage struct if the namespace URI is of the form:
- * http://schemas.android.com/apk/res/<package> or
- * http://schemas.android.com/apk/prv/res/<package>
- *
- * Special case: if namespaceUri is http://schemas.android.com/apk/res-auto,
- * returns an empty package name.
- */
-Maybe<ExtractedPackage> ExtractPackageFromNamespace(
-    const std::string& namespace_uri);
+// Returns an ExtractedPackage struct if the namespace URI is of the form:
+//   http://schemas.android.com/apk/res/<package> or
+//   http://schemas.android.com/apk/prv/res/<package>
+//
+// Special case: if namespaceUri is http://schemas.android.com/apk/res-auto,
+// returns an empty package name.
+Maybe<ExtractedPackage> ExtractPackageFromNamespace(const std::string& namespace_uri);
 
-/**
- * Returns an XML Android namespace for the given package of the form:
- *
- * http://schemas.android.com/apk/res/<package>
- *
- * If privateReference == true, the package will be of the form:
- *
- * http://schemas.android.com/apk/prv/res/<package>
- */
+// Returns an XML Android namespace for the given package of the form:
+//   http://schemas.android.com/apk/res/<package>
+//
+// If privateReference == true, the package will be of the form:
+//   http://schemas.android.com/apk/prv/res/<package>
 std::string BuildPackageNamespace(const android::StringPiece& package,
                                   bool private_reference = false);
 
-/**
- * Interface representing a stack of XML namespace declarations. When looking up
- * the package
- * for a namespace prefix, the stack is checked from top to bottom.
- */
+// Interface representing a stack of XML namespace declarations. When looking up the package
+// for a namespace prefix, the stack is checked from top to bottom.
 struct IPackageDeclStack {
   virtual ~IPackageDeclStack() = default;
 
-  /**
-   * Returns an ExtractedPackage struct if the alias given corresponds with a
-   * package declaration.
-   */
+  // Returns an ExtractedPackage struct if the alias given corresponds with a package declaration.
   virtual Maybe<ExtractedPackage> TransformPackageAlias(
       const android::StringPiece& alias, const android::StringPiece& local_package) const = 0;
 };
 
-/**
- * Helper function for transforming the original Reference inRef to a fully
- * qualified reference
- * via the IPackageDeclStack. This will also mark the Reference as private if
- * the namespace of the package declaration was private.
- */
+// Helper function for transforming the original Reference inRef to a fully qualified reference
+// via the IPackageDeclStack. This will also mark the Reference as private if the namespace of the
+// package declaration was private.
 void TransformReferenceFromNamespace(IPackageDeclStack* decl_stack,
                                      const android::StringPiece& local_package, Reference* in_ref);