Add @JSName annotation for native fields and methods.

sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart

Index: sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart b/sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart
index c2542ef768db514920b37b0537583c57d667b6bb..c2e6b0de6c53aec4e63794dc5b5cc5eab9600da6 100644
--- a/sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart
@@ -31,9 +31,6 @@ class NativeEmitter {
   // Caches the methods that have a native body.
   Set<FunctionElement> nativeMethods;
 
-  // Caches the methods that redirect to a JS method.
-  Map<FunctionElement, String> redirectingMethods;
-
   // Do we need the native emitter to take care of handling
   // noSuchMethod for us? This flag is set to true in the emitter if
   // it finds any native class that needs noSuchMethod handling.
@@ -46,16 +43,11 @@ class NativeEmitter {
         directSubtypes = new Map<ClassElement, List<ClassElement>>(),
         overriddenMethods = new Set<FunctionElement>(),
         nativeMethods = new Set<FunctionElement>(),
-        redirectingMethods = new Map<FunctionElement, String>(),
         nativeBuffer = new CodeBuffer();
 
   Compiler get compiler => emitter.compiler;
   JavaScriptBackend get backend => compiler.backend;
 
-  void addRedirectingMethod(FunctionElement element, String name) {
-    redirectingMethods[element] = name;
-  }
-
   String get dynamicName {
     Element element = compiler.findHelper(
         const SourceString('dynamicFunction'));
@@ -115,7 +107,7 @@ function(cls, desc) {
   }
 
   void generateNativeLiteral(ClassElement classElement) {
-    String quotedNative = classElement.nativeName.slowToString();
+    String quotedNative = classElement.nativeTagInfo.slowToString();
     String nativeCode = quotedNative.substring(2, quotedNative.length - 1);
     String className = backend.namer.getName(classElement);
     nativeBuffer.add(className);
@@ -142,8 +134,8 @@ function(cls, desc) {
     return identical(quotedName[1], '@');
   }
 
-  String toNativeName(ClassElement cls) {
-    String quotedName = cls.nativeName.slowToString();
+  String toNativeTag(ClassElement cls) {
+    String quotedName = cls.nativeTagInfo.slowToString();
     if (isNativeGlobal(quotedName)) {
       // Global object, just be like the other types for now.
       return quotedName.substring(3, quotedName.length - 1);
@@ -156,7 +148,7 @@ function(cls, desc) {
     nativeClasses.add(classElement);
 
     assert(classElement.backendMembers.isEmpty);
-    String quotedName = classElement.nativeName.slowToString();
+    String quotedName = classElement.nativeTagInfo.slowToString();
     if (isNativeLiteral(quotedName)) {
       generateNativeLiteral(classElement);
       // The native literal kind needs to be dealt with specially when
@@ -178,8 +170,8 @@ function(cls, desc) {
       return;
     }
 
-    String nativeName = toNativeName(classElement);
-    nativeBuffer.add("$defineNativeClassName('$nativeName', ");
+    String nativeTag = toNativeTag(classElement);
+    nativeBuffer.add("$defineNativeClassName('$nativeTag', ");
     nativeBuffer.add('{');
     bool firstInMap = true;
     if (!fieldBuffer.isEmpty) {
@@ -247,7 +239,7 @@ function(cls, desc) {
         0, indexOfLastOptionalArgumentInParameters + 1);
 
     ClassElement classElement = member.enclosingElement;
-    String nativeName = classElement.nativeName.slowToString();
+    String nativeTagInfo = classElement.nativeTagInfo.slowToString();
     String nativeArguments = Strings.join(nativeArgumentsBuffer, ",");
 
     CodeBuffer code = new CodeBuffer();
@@ -260,12 +252,11 @@ function(cls, desc) {
       code.add('  return this.${backend.namer.getName(member)}($arguments)');
     } else {
       // When calling a JS method, we call it with the native name.
-      String name = redirectingMethods[member];
-      if (name == null) name = member.name.slowToString();
+      String name = member.nativeName();
       code.add('  return this.$name($nativeArguments);');
     }
 
-    if (isNativeLiteral(nativeName) || !overriddenMethods.contains(member)) {
+    if (isNativeLiteral(nativeTagInfo) || !overriddenMethods.contains(member)) {
       // Call the method directly.
       buffer.add(code.toString());
     } else {
@@ -327,14 +318,14 @@ function(cls, desc) {
       // Expression fragments for this set of cls keys.
       List<js.Expression> expressions = <js.Expression>[];
       // TODO: Remove if cls is abstract.
-      List<String> subtags = [toNativeName(classElement)];
+      List<String> subtags = [toNativeTag(classElement)];
       void walk(ClassElement cls) {
         for (final ClassElement subclass in getDirectSubclasses(cls)) {
           ClassElement tag = subclass;
           js.Expression existing = tagDefns[tag];
           if (existing == null) {
             // [subclass] is still within the subtree between dispatch classes.
-            subtags.add(toNativeName(tag));
+            subtags.add(toNativeTag(tag));
             walk(subclass);
           } else {
             // [subclass] is one of the preorderDispatchClasses, so CSE this
@@ -404,7 +395,7 @@ function(cls, desc) {
           new js.ArrayInitializer.from(
               preorderDispatchClasses.map((cls) =>
                   new js.ArrayInitializer.from([
-                      new js.LiteralString("'${toNativeName(cls)}'"),
+                      new js.LiteralString("'${toNativeTag(cls)}'"),
                       tagDefns[cls]])));
 
       //  $.dynamicSetMetadata(table);