Do not merge namespaces

It is good practice to not include the whole std:: namespace into
the global namespace.  This is doubly true in headers.

TEST=aidl compiles

Change-Id: I910ca8082f61cce4f23f8564b8a12c2828b75b3c

tools/aidl/AST.h

@@ -7,7 +7,9 @@
 #include <stdarg.h>
 #include <stdio.h>
 
-using namespace std;
+using std::set;
+using std::string;
+using std::vector;
 
 class Type;
 

tools/aidl/Type.h

@@ -5,7 +5,8 @@
 #include <string>
 #include <vector>
 
-using namespace std;
+using std::string;
+using std::vector;
 
 class Type
 {

tools/aidl/aidl.cpp

@@ -31,7 +31,10 @@
 #define MIN_USER_SET_METHOD_ID                0
 #define MAX_USER_SET_METHOD_ID                16777214
 
-using namespace std;
+using std::map;
+using std::set;
+using std::string;
+using std::vector;
 
 static void
 test_document(document_item_type* d)

tools/aidl/generate_java.h

@@ -6,7 +6,8 @@
 
 #include <string>
 
-using namespace std;
+using std::string;
+using std::vector;
 
 int generate_java(const string& filename, const string& originalSrc,
                 interface_type* iface);

tools/aidl/options.h

@@ -5,7 +5,8 @@
 #include <string>
 #include <vector>
 
-using namespace std;
+using std::string;
+using std::vector;
 
 enum {
     COMPILE_AIDL,

tools/aidl/options_test.cpp

@@ -3,7 +3,8 @@
 
 const bool VERBOSE = false;
 
-using namespace std;
+using std::string;
+using std::vector;
 
 struct Answer {
     const char* argv[8];

tools/aidl/search_path.h

@@ -6,7 +6,10 @@
 #if __cplusplus
 #include <vector>
 #include <string>
-using namespace std;
+
+using std::string;
+using std::vector;
+
 extern "C" {
 #endif