Docs: Migrating platform docs to /guide/platform/ with new landing page

Bug:29575457
Change-Id: I6d576e9dd28132fcf7e6e017187f30702066c2af

docs/html-intl/intl/es/preview/_book.yaml

@@ -260,27 +260,6 @@ toc:
       value: ICU4J Android 框架 API
     - name: zh-tw-lang
       value: ICU4J Android 架構 API
-  - title: Funciones del lenguaje Java 8
-    path: /preview/j8-jack.html
-    path_attributes:
-    - name: es-lang
-      value: Funciones del lenguaje Java 8
-    - name: in-lang
-      value: Fitur Bahasa Java 8
-    - name: ja-lang
-      value: Java 8 の機能
-    - name: ko-lang
-      value: Java 8 언어 기능
-    - name: pt-br-lang
-      value: Recursos de linguagem do Java 8
-    - name: ru-lang
-      value: Возможности языка Java 8
-    - name: vi-lang
-      value: Tính năng của Ngôn ngữ Java 8
-    - name: zh-cn-lang
-      value: Java 8 语言功能
-    - name: zh-tw-lang
-      value: Java 8 語言功能
   - title: Actualizaciones para Android for Work
     path: /preview/features/afw.html
   - title: Acceso a directorios determinados

docs/html-intl/intl/in/preview/_book.yaml

@@ -260,27 +260,6 @@ toc:
       value: ICU4J Android 框架 API
     - name: zh-tw-lang
       value: ICU4J Android 架構 API
-  - title: Fitur Bahasa Java 8
-    path: /preview/j8-jack.html
-    path_attributes:
-    - name: es-lang
-      value: Funciones del lenguaje Java 8
-    - name: in-lang
-      value: Fitur Bahasa Java 8
-    - name: ja-lang
-      value: Java 8 の機能
-    - name: ko-lang
-      value: Java 8 언어 기능
-    - name: pt-br-lang
-      value: Recursos de linguagem do Java 8
-    - name: ru-lang
-      value: Возможности языка Java 8
-    - name: vi-lang
-      value: Tính năng của Ngôn ngữ Java 8
-    - name: zh-cn-lang
-      value: Java 8 语言功能
-    - name: zh-tw-lang
-      value: Java 8 語言功能
   - title: Pembaruan Android for Work
     path: /preview/features/afw.html
   - title: Scoped Directory Access

docs/html-intl/intl/ja/preview/_book.yaml

@@ -260,27 +260,6 @@ toc:
       value: ICU4J Android 框架 API
     - name: zh-tw-lang
       value: ICU4J Android 架構 API
-  - title: Java 8 の言語機能
-    path: /preview/j8-jack.html
-    path_attributes:
-    - name: es-lang
-      value: Funciones del lenguaje Java 8
-    - name: in-lang
-      value: Fitur Bahasa Java 8
-    - name: ja-lang
-      value: Java 8 の機能
-    - name: ko-lang
-      value: Java 8 언어 기능
-    - name: pt-br-lang
-      value: Recursos de linguagem do Java 8
-    - name: ru-lang
-      value: Возможности языка Java 8
-    - name: vi-lang
-      value: Tính năng của Ngôn ngữ Java 8
-    - name: zh-cn-lang
-      value: Java 8 语言功能
-    - name: zh-tw-lang
-      value: Java 8 語言功能
   - title: Android for Work のアップデート
     path: /preview/features/afw.html
   - title: 特定のディレクトリへのアクセス

docs/html-intl/intl/ko/preview/_book.yaml

@@ -260,27 +260,6 @@ toc:
       value: ICU4J Android 框架 API
     - name: zh-tw-lang
       value: ICU4J Android 架構 API
-  - title: Java 8 언어 기능
-    path: /preview/j8-jack.html
-    path_attributes:
-    - name: es-lang
-      value: Funciones del lenguaje Java 8
-    - name: in-lang
-      value: Fitur Bahasa Java 8
-    - name: ja-lang
-      value: Java 8 の機能
-    - name: ko-lang
-      value: Java 8 언어 기능
-    - name: pt-br-lang
-      value: Recursos de linguagem do Java 8
-    - name: ru-lang
-      value: Возможности языка Java 8
-    - name: vi-lang
-      value: Tính năng của Ngôn ngữ Java 8
-    - name: zh-cn-lang
-      value: Java 8 语言功能
-    - name: zh-tw-lang
-      value: Java 8 語言功能
   - title: Android for Work 업데이트
     path: /preview/features/afw.html
   - title: 범위가 지정된 디렉터리 액세스

docs/html-intl/intl/pt-br/preview/_book.yaml

@@ -260,27 +260,6 @@ toc:
       value: ICU4J Android 框架 API
     - name: zh-tw-lang
       value: ICU4J Android 架構 API
-  - title: Recursos de linguagem do Java 8
-    path: /preview/j8-jack.html
-    path_attributes:
-    - name: es-lang
-      value: Funciones del lenguaje Java 8
-    - name: in-lang
-      value: Fitur Bahasa Java 8
-    - name: ja-lang
-      value: Java 8 の機能
-    - name: ko-lang
-      value: Java 8 언어 기능
-    - name: pt-br-lang
-      value: Recursos de linguagem do Java 8
-    - name: ru-lang
-      value: Возможности языка Java 8
-    - name: vi-lang
-      value: Tính năng của Ngôn ngữ Java 8
-    - name: zh-cn-lang
-      value: Java 8 语言功能
-    - name: zh-tw-lang
-      value: Java 8 語言功能
   - title: Atualizações no Android for Work
     path: /preview/features/afw.html
   - title: Acesso a diretórios com escopo

docs/html-intl/intl/zh-cn/preview/_book.yaml

@@ -260,27 +260,6 @@ toc:
       value: ICU4J Android フレームワーク API
     - name: zh-tw-lang
       value: ICU4J Android フレームワーク API
-  - title: Java 8 语言功能
-    path: /preview/j8-jack.html
-    path_attributes:
-    - name: es-lang
-      value: Funciones del lenguaje Java 8
-    - name: in-lang
-      value: Fitur Bahasa Java 8
-    - name: ja-lang
-      value: Java 8 の機能
-    - name: ko-lang
-      value: Java 8 언어 기능
-    - name: pt-br-lang
-      value: Recursos de linguagem do Java 8
-    - name: ru-lang
-      value: Возможности языка Java 8
-    - name: vi-lang
-      value: Tính năng của Ngôn ngữ Java 8
-    - name: zh-cn-lang
-      value: Java 8 の機能
-    - name: zh-tw-lang
-      value: Java 8 の機能
   - title: Android for Work Updates
     path: /preview/features/afw.html
   - title: 作用域目录访问

docs/html/_redirects.yaml

@@ -1220,4 +1220,5 @@ redirects:
   to: /guide/topics/ui/notifiers/notifications.html
 - from: /preview/features/multilingual-support.html
   to: /guide/topics/resources/multilingual-support.html
-
+- from: /preview/j8-jack.html
+  to: /guide/platform/j8-jack.html

docs/html/guide/_book.yaml

@@ -9,6 +9,33 @@ toc:
   - title: System Permissions
     path: /guide/topics/security/permissions.html
 
+- title: Platform Architecture
+  path: /guide/platform/index.html
+  section:
+  - title: Use Java 8 Language Features
+    path: /guide/platform/j8-jack.html
+    path_attributes:
+    - name: es-lang
+      value: Funciones del lenguaje Java 8
+    - name: in-lang
+      value: Fitur Bahasa Java 8
+    - name: ja-lang
+      value: Java 8 の機能
+    - name: ko-lang
+      value: Java 8 언어 기능
+    - name: pt-br-lang
+      value: Recursos de linguagem do Java 8
+    - name: ru-lang
+      value: Возможности языка Java 8
+    - name: vi-lang
+      value: Tính năng của Ngôn ngữ Java 8
+    - name: zh-cn-lang
+      value: Java 8 语言功能
+    - name: zh-tw-lang
+      value: Java 8 語言功能
+  - title: Verifying App Behavior on the Android Runtime (ART)
+    path: /guide/practices/verifying-apps-art.html
+
 - title: App Components
   path: /guide/components/index.html
   section:
@@ -422,5 +449,3 @@ toc:
       path: /guide/practices/screen-compat-mode.html
   - title: Supporting Tablets and Handsets
     path: /guide/practices/tablets-and-handsets.html
-  - title: Verifying App Behavior on ART
-    path: /guide/practices/verifying-apps-art.html

docs/html/guide/platform/index.jd

@@ -0,0 +1,217 @@
+page.title=Platform Architecture
+page.keywords=platform,architecture,framework
+@jd:body
+
+
+<div id="qv-wrapper">
+  <div id="qv">
+    <h2>
+      In this document
+    </h2>
+
+    <ol>
+      <li>
+        <a href="#linux-kernel">The Linux Kernel</a>
+      </li>
+
+      <li>
+        <a href="#hal">Hardware Abstraction Layer (HAL)</a>
+      </li>
+
+      <li>
+        <a href="#art">Android Runtime</a>
+      </li>
+
+      <li>
+        <a href="#native-libs">Native C/C++ Libraries</a>
+      </li>
+
+      <li>
+        <a href="#api-framework">Java API Framework</a>
+      </li>
+
+      <li>
+        <a href="#system-apps">System Apps</a>
+      </li>
+    </ol>
+  </div>
+</div>
+
+<p>
+  Android is an open source, Linux-based software stack created for a wide
+  array of devices and form factors. The following diagram shows the major
+  components of the Android platform.
+</p>
+
+<img src="/guide/platform/images/android-stack_2x.png" alt="" width=
+"519">
+<p class="img-caption">
+  <strong>Figure 1.</strong> The Android software stack.
+</p>
+
+<h2 id="linux-kernel">
+The Linux Kernel
+</h2>
+
+<p>
+  The foundation of the Android platform is the Linux kernel. For example,
+  <a href="#art">the Android Runtime (ART)</a> relies on the Linux kernel for
+  underlying functionalities such as threading and low-level memory management.
+</p>
+
+<p>
+  Using a Linux kernel allows Android to take advantage of <a href=
+  "https://source.android.com/security/overview/kernel-security.html">key
+  security features</a> and allows device manufacturers to develop hardware
+  drivers for a well-known kernel.
+</p>
+
+<h2 id="hal">
+Hardware Abstraction Layer (HAL)
+</h2>
+
+<p>
+  The <a href=
+  "https://source.android.com/devices/index.html#Hardware%20Abstraction%20Layer">
+  hardware abstraction layer (HAL)</a> provides standard interfaces that expose
+  device hardware capabilities to the higher-level <a href=
+  "#api-framework">Java API framework</a>. The HAL consists of multiple library
+  modules, each of which implements an interface for a specific type of hardware
+  component, such as the <a href=
+  "https://source.android.com/devices/camera/index.html">camera</a> or <a href=
+  "https://source.android.com/devices/bluetooth.html">bluetooth</a> module.
+  When a framework API makes a call to access device hardware, the Android
+  system loads the library module for that hardware component.
+</p>
+
+<h2 id="art">
+Android Runtime
+</h2>
+
+<p>
+  For devices running Android version 5.0 (API level 21) or higher, each app
+  runs in its own process and with its own instance of the <a href=
+  "http://source.android.com/devices/tech/dalvik/index.html">Android Runtime
+  (ART)</a>. ART is written to run multiple virtual machines on low-memory
+  devices by executing DEX files, a bytecode format designed specially for
+  Android that's optimized for minimal memory footprint. Build toolchains, such
+  as <a href="https://source.android.com/source/jack.html">Jack</a>, compile
+  Java sources into DEX bytecode, which can run on the Android platform.
+</p>
+
+<p>
+  Some of the major features of ART include the following:
+</p>
+
+<ul>
+  <li>Ahead-of-time (AOT) and just-in-time (JIT) compilation
+  </li>
+
+  <li>Optimized garbage collection (GC)
+  </li>
+
+  <li>Better debugging support, including a dedicated sampling profiler,
+  detailed diagnostic exceptions and crash reporting, and the ability to set
+  watchpoints to monitor specific fields
+  </li>
+</ul>
+
+<p>
+  Prior to Android version 5.0 (API level 21), Dalvik was the Android runtime.
+  If your app runs well on ART, then it should work on Dalvik as well, but
+  <a href="/guide/platform/verifying-apps-art.html">the reverse may not be
+  true</a>.
+</p>
+
+<p>
+  Android also includes a set of core runtime libraries that provide most of
+  the functionality of the Java programming language, including some <a href=
+  "/guide/platform/j8-jack.html">Java 8 language features</a>, that the Java
+  API framework uses.
+</p>
+
+<h2 id="native-libs">
+  Native C/C++ Libraries
+</h2>
+
+<p>
+  Many core Android system components and services, such as ART and HAL, are
+  built from native code that require native libraries written in C and C++.
+  The Android platform provides Java framework APIs to expose the functionality
+  of some of these native libraries to apps. For example, you can access
+  <a href="/guide/topics/graphics/opengl.html">OpenGL ES</a> through the
+  Android framework’s <a href=
+  "/reference/android/opengl/package-summary.html">Java OpenGL API</a> to add
+  support for drawing and manipulating 2D and 3D graphics in your app.
+</p>
+
+<p>
+  If you are developing an app that requires C or C++ code, you can use the
+  <a href="/ndk/index.html">Android NDK</a> to access some of these <a href=
+  "/ndk/guides/stable_apis.html">native platform libraries</a> directly from
+  your native code.
+</p>
+
+<h2 id="api-framework">
+Java API Framework
+</h2>
+
+<p>
+  The entire feature-set of the Android OS is available to you through APIs
+  written in the Java language. These APIs form the building blocks you need to
+  create Android apps by simplifying the reuse of core, modular system
+  components and services, which include the following:
+</p>
+
+<ul>
+  <li>A rich and extensible <a href="/guide/topics/ui/overview.html">View
+  System</a> you can use to build an app’s UI, including lists, grids, text
+  boxes, buttons, and even an embeddable web browser
+  </li>
+
+  <li>A <a href="/guide/topics/resources/overview.html">Resource Manager</a>,
+  providing access to non-code resources such as localized strings, graphics,
+  and layout files
+  </li>
+
+  <li>A <a href="/guide/topics/ui/notifiers/notifications.html">Notification
+  Manager</a> that enables all apps to display custom alerts in the status bar
+  </li>
+
+  <li>An <a href="/guide/components/activities.html">Activity Manager</a> that
+  manages the lifecycle of apps and provides a common <a href=
+  "/guide/components/tasks-and-back-stack.html">navigation back stack</a>
+  </li>
+
+  <li>
+    <a href="/guide/topics/providers/content-providers.html">Content
+    Providers</a> that enable apps to access data from other apps, such as
+    the Contacts app, or to share their own data
+  </li>
+</ul>
+
+<p>
+  Developers have full access to the same <a href=
+  "/reference/packages.html">framework APIs</a> that Android system apps use.
+</p>
+
+<h2 id="system-apps">
+System Apps
+</h2>
+
+<p>
+  Android comes with a set of core apps for email, SMS messaging, calendars,
+  internet browsing, contacts, and more. Apps included with the platform have
+  no special status among the apps the user chooses to install. So a
+  third-party app can become the user's default web browser, SMS messenger, or
+  even the default keyboard (some exceptions apply, such as the system's
+  Settings app).
+</p>
+
+<p>
+  The system apps function both as apps for users and to provide key
+  capabilities that developers can access from their own app. For example, if
+  your app would like to deliver an SMS message, you don't need to build that
+  functionality yourself—you can instead invoke whichever SMS app is already
+  installed to deliver a message to the recipient you specify.
+</p>

docs/html/guide/platform/j8-jack.jd

@@ -1,41 +1,63 @@
-page.title=Java 8 Language Features
+page.title=Use Java 8 Language Features
 page.keywords="android N", "Java 8", "Jack"
 @jd:body
 
 <div id="qv-wrapper">
   <div id="qv">
+    <h2 id="Contents">
+      In this document:
+    </h2>
+
     <ol>
       <li>
-        <a href="#supported-features">Supported Java 8 Language Features and APIs</a>
+        <a href="#supported-features">Supported Java 8 Language Features and
+        APIs</a>
       </li>
+
       <li>
-        <a href="#configuration">Enabling Java 8 Features and the Jack Toolchain</a>
+        <a href="#configuration">Enable Java 8 Features and the Jack
+        Toolchain</a>
+        <ul>
+          <li>
+            <a href="#configure-gradle">Configure Gradle</a>
+          </li>
+
+          <li>
+            <a href="#known-issues">Known issues</a>
+          </li>
+        </ul>
       </li>
     </ol>
   </div>
 </div>
 
-<p>Android N introduces support for Java 8 language features
-  that you can use when developing apps that target Android N.
-  This page describes the new language features supported in the Android N
-  Preview, how to properly set up your project to use them, and any known
-  issues you may encounter.
+<p>
+  Android supports all Java 7 language features and a subset of Java 8 language
+  features that vary by platform version. This page describes the new language
+  features you can use, how to properly configure your project to use them, and
+  any known issues you may encounter.
 </p>
 
-<p>To start using these features, you need to download and set up Android
-Studio 2.1 and the Android N Preview SDK, which includes the required
-Jack toolchain and updated Android Plugin for Gradle. If you haven't yet
-installed the Android N Preview SDK, see <a href=
-"{@docRoot}preview/setup-sdk.html">Set Up to Develop for Android N</a>.</p>
-
-
-
 <p class="note">
-  <strong>Note:</strong> Using the new Java 8 language features is not a
-  requirement for developing apps that target the Android N platform. If you
-  don't want to write code with Java 8 language features, you can keep your
-  project's source and target compatibility values set to Java 7, but you still
-  must compile with JDK 8 to build against the Android N platform.
+  <strong>Note:</strong> When developing apps for Android, using Java 8
+  language features is optional. You can keep your project's source and target
+  compatibility values set to Java 7, but you still need to compile using JDK
+  8.
+</p>
+
+<p>
+  Support for Java 8 language features requires a new compiler called <a href=
+  "https://source.android.com/source/jack.html">Jack</a>. Jack is supported
+  only on Android Studio 2.1 and higher. So if you want to use Java 8 language
+  features, you need to use Android Studio 2.1 to build your app.
+</p>
+
+<p>
+  If you already have Android Studio installed, make sure you update to the
+  latest version by clicking <strong>Help &gt; Check for Update</strong> (on
+  Mac, <strong>Android Studio &gt; Check for Updates</strong>). If you don't
+  already have the IDE installed on your workstation, <a href=
+  "{@docRoot}studio/">download Android Studio here</a>.
 </p>
 
 <h2 id="supported-features">
@@ -43,9 +65,9 @@ installed the Android N Preview SDK, see <a href=
 </h2>
 
 <p>
-  Android does not currently support all Java 8 language features. However, the
-  following features are now available when developing apps targeting the
-  Android N Preview:
+  Android does not support all Java 8 language features. However, the
+  following features are available when developing apps targeting
+  Android 7.0 (API level 24):
 </p>
 
 <ul>
@@ -94,7 +116,7 @@ installed the Android N Preview SDK, see <a href=
 </p>
 
 <p>
-  Additionally, the following Java 8 language feature APIs are now available:
+  Additionally, the following Java 8 language APIs are also available:
 </p>
 
 <ul>
@@ -144,37 +166,36 @@ installed the Android N Preview SDK, see <a href=
 </ul>
 
 <h2 id="configuration">
-  Enabling Java 8 Features and the Jack Toolchain
+  Enable Java 8 Features and the Jack Toolchain
 </h2>
 
 <p>
   In order to use the new Java 8 language features, you need to also use the
-  new <a class="external-link" href=
-  "https://source.android.com/source/jack.html">Jack toolchain</a>. This new
-  Android toolchain compiles Java language source into Android-readable dex
-  bytecode, has its own {@code .jack} library format, and provides most toolchain
-  features as part of a single tool: repackaging, shrinking, obfuscation and
-  multidex.
+  <a href="https://source.android.com/source/jack.html">Jack toolchain</a>.
+  This new Android toolchain compiles Java language sources into
+  Android-readable DEX bytecode, has its own {@code .jack} library format, and
+  provides most toolchain features as part of a single tool: repackaging,
+  shrinking, obfuscation and multidex.
 </p>
 
 <p>Here is a comparison of the two toolchains used to build Android DEX files:</p>
 <ul>
   <li>Legacy javac toolchain:<br>
-  <b>javac</b> ({@code .java} --&gt; {@code .class}) --&gt; <b>dx</b> ({@code
-  .class} --&gt; {@code .dex})
+  <b>javac</b> ({@code .java} → {@code .class}) → <b>dx</b> ({@code
+  .class} → {@code .dex})
   </li>
 
   <li>New Jack toolchain:<br>
-  <b>Jack</b> ({@code .java} --&gt; {@code .jack} --&gt; {@code .dex})
+  <b>Jack</b> ({@code .java} → {@code .jack} → {@code .dex})
   </li>
 </ul>
 
-<h3>
-  Configuring Gradle
+<h3 id="configure-gradle">
+  Configure Gradle
 </h3>
 
 <p>
-  To enable the Java 8 language features and Jack for your project, enter the
+  To enable Java 8 language features and Jack for your project, enter the
   following in your module-level {@code build.gradle} file:
 </p>
 
@@ -195,7 +216,7 @@ android {
 </pre>
 
 <h3 id="known-issues">
-  Known Issues
+  Known issues
 </h3>
 
 <p>
@@ -217,5 +238,5 @@ examples of these tools are:</p>
   </li>
 </ul>
 
-<p>If you find other problems while using Jack, <a href=
+<p>If you find other issues while using Jack, <a href=
 "http://tools.android.com/filing-bugs">please file a bug</a>.</p>

docs/html/guide/practices/verifying-apps-art.jd

@@ -2,60 +2,82 @@ page.title=Verifying App Behavior on the Android Runtime (ART)
 @jd:body
 
 <div id="qv-wrapper">
-<div id="qv">
-<h2>Quickview</h2>
-  <ul>
-    <li>The new Android runtime (ART) is available on some of the newest Android
-      devices, though all of them currently have Dalvik as the default
-      runtime.</li>
-    <li>App developers should make sure their apps are compatible with ART,
-      especially if you use JNI to run native code or if you use certain tools
-      that produce non-standard code (such as some obfuscators).</li>
-  </ul>
+  <div id="qv">
+    <h2 id="Contents">
+      In this document
+    </h2>
 
-  <h2 id="Contents">In this document</h2>
- <ol>
-    <li><a href="#GC_Migration">Addressing Garbage Collection (GC) Issues</a></li>
-    <li><a href="#JNI_Issues">Preventing JNI Issues</a>
-      <ol>
-        <li><a href="#JNI_and_GC">Checking JNI code for garbage-collection
-          issues</a></li>
-        <li><a href="#Error_Handling">Error handling</a></li>
-        <li><a href="#Object_Model_Changes">Object model changes</a></li>
-      </ol>
-    </li>
-    <li><a href="#Stack_Size">Preventing Stack Size Issues</a></li>
-    <li><a href="#AOT_Fails">Fixing AOT Compilation Issues</a></li>
-    <li><a href="#Reporting_Problems">Reporting Problems</a></li>
-  </ol>
-  <h2>See also</h2>
-  <ol>
-    <li><a href="http://source.android.com/devices/tech/dalvik/art.html">Introducing ART</a></li>
-    <li><a
-href="http://android-developers.blogspot.com/2011/07/debugging-android-jni-with-checkjni.html">Debugging
-Android JNI with CheckJNI</a></li>
-  </ol>
-</div>
+    <ol>
+      <li>
+        <a href="#GC_Migration">Addressing Garbage Collection (GC) Issues</a>
+      </li>
+
+      <li>
+        <a href="#JNI_Issues">Preventing JNI Issues</a>
+        <ol>
+          <li>
+            <a href="#JNI_and_GC">Checking JNI code for garbage-collection
+            issues</a>
+          </li>
+
+          <li>
+            <a href="#Error_Handling">Error handling</a>
+          </li>
+
+          <li>
+            <a href="#Object_Model_Changes">Object model changes</a>
+          </li>
+        </ol>
+      </li>
+
+      <li>
+        <a href="#Stack_Size">Preventing Stack Size Issues</a>
+      </li>
+
+      <li>
+        <a href="#AOT_Fails">Fixing AOT Compilation Issues</a>
+      </li>
+
+      <li>
+        <a href="#Reporting_Problems">Reporting Problems</a>
+      </li>
+    </ol>
+
+    <h2>
+      See also
+    </h2>
+
+    <ol>
+      <li>
+        <a href=
+        "http://source.android.com/devices/tech/dalvik/art.html">Introducing
+        ART</a>
+      </li>
+
+      <li>
+        <a href=
+        "http://android-developers.blogspot.com/2011/07/debugging-android-jni-with-checkjni.html">
+        Debugging Android JNI with CheckJNI</a>
+      </li>
+    </ol>
+  </div>
 </div>
 
-<p>With Android 4.4, we are beginning to roll out a new Android runtime,
-<strong>ART</strong>. This runtime offers a number of new features that improve
-performance and smoothness of the Android platform and apps. (You can find more
-information about ART's new features in <a
-href="http://source.android.com/devices/tech/dalvik/art.html">Introducing
-ART</a>.)</p>
+<p>
+  The Android runtime (ART) is the default runtime for devices running Android
+  5.0 (API level 21) and higher. This runtime offers a number of features
+  that improve performance and smoothness of the Android platform and apps.
+  You can find more information about ART's new features in <a href=
+  "http://source.android.com/devices/tech/dalvik/art.html">Introducing
+  ART</a>.
+</p>
 
-<p>Currently, ART is available on a number of Android 4.4 devices, such as the
-Nexus 4, Nexus 5, Nexus 7, and Google Play edition devices.
-At this time, all devices still use Dalvik as the default runtime. We encourage
-you to test your apps for ART compatibility and to take advantage of ART's new
-features. However, for the time being, you should also take care to maintain
-compatibility with Dalvik.</p>
-
-<p>This document lets you know about things to watch for when migrating an
-existing app to be compatible with ART. Most apps should just work when
-running with ART. However, some techniques that work on Dalvik do not work on
-ART. This document discusses some of these issues.</p>
+<p>
+  However, some techniques that work on Dalvik do not work on ART. This
+  document lets you know about things to watch for when migrating an existing
+  app to be compatible with ART. Most apps should just work when running with
+  ART.
+</p>
 
 <h2 id="GC_Migration">Addressing Garbage Collection (GC) Issues</h2>
 
@@ -147,7 +169,7 @@ in use, this can lead to memory corruption or other problems. For example:</p>
 
 <h3 id="Error_Handling">Error handling</h3>
 
-<p>ART's JNI throws errors in a number of cases where Dalvik didn’t. (Once
+<p>ART's JNI throws errors in a number of cases where Dalvik doesn’t. (Once
 again, you can catch many such cases by testing with CheckJNI.)</p>
 
 <p>For example, if <code>RegisterNatives</code> is called with a method that

docs/html/preview/_book.yaml

@@ -262,27 +262,6 @@ toc:
       value: ICU4J Android 框架 API
     - name: zh-tw-lang
       value: ICU4J Android 架構 API
-  - title: Java 8 Language Features
-    path: /preview/j8-jack.html
-    path_attributes:
-    - name: es-lang
-      value: Funciones del lenguaje Java 8
-    - name: in-lang
-      value: Fitur Bahasa Java 8
-    - name: ja-lang
-      value: Java 8 の機能
-    - name: ko-lang
-      value: Java 8 언어 기능
-    - name: pt-br-lang
-      value: Recursos de linguagem do Java 8
-    - name: ru-lang
-      value: Возможности языка Java 8
-    - name: vi-lang
-      value: Tính năng của Ngôn ngữ Java 8
-    - name: zh-cn-lang
-      value: Java 8 语言功能
-    - name: zh-tw-lang
-      value: Java 8 語言功能
   - title: Android for Work Updates
     path: /preview/features/afw.html
   - title: Scoped Directory Access