Add a new interceptor class JsArray, and support intercepting some list methods with the new interc…

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

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of js_backend;
 
 typedef void Recompile(Element element);
 
 class ReturnInfo {
   HType returnType;
@@ skipping 629 matching lines @@
         boundsChecked = new Set<HInstruction>();
 }
 
 class JavaScriptBackend extends Backend {
   SsaBuilderTask builder;
   SsaOptimizerTask optimizer;
   SsaCodeGeneratorTask generator;
   CodeEmitterTask emitter;
 
   ClassElement jsStringClass;
+  ClassElement jsArrayClass;
   ClassElement objectInterceptorClass;
   Element getInterceptorMethod;
 
   final Namer namer;
 
   /**
    * Interface used to determine if an object has the JavaScript
    * indexing behavior. The interface is only visible to specific
    * libraries.
    */
@@ skipping 49 matching lines @@
   }
 
   static Namer determineNamer(Compiler compiler) {
     return compiler.enableMinification ?
         new MinifyNamer(compiler) :
         new Namer(compiler);
   }
 
   bool isInterceptorClass(Element element) {
     if (element == null) return false;
-    return element == jsStringClass;
+    return element == jsStringClass || element == jsArrayClass;
   }
 
   void addInterceptedSelector(Selector selector) {
     usedInterceptors.add(selector);
   }
 
   bool shouldInterceptSelector(Selector selector) {
     List<Element> intercepted = interceptedElements[selector.name];
     if (intercepted == null) return false;
     for (Element element in intercepted) {
@@ skipping 12 matching lines @@
 
   void registerInstantiatedClass(ClassElement cls, Enqueuer enqueuer) {
     ClassElement result = null;
     if (cls == compiler.stringClass) {
       if (jsStringClass == null) {
         jsStringClass =
             compiler.findInterceptor(const SourceString('JSString'));
         initializeInterceptorElements();
       }
       result = jsStringClass;
+    } else if (cls == compiler.listClass) {
+      if (jsArrayClass == null) {
+        jsArrayClass =
+            compiler.findInterceptor(const SourceString('JSArray'));
+        initializeInterceptorElements();
+      }
+      result = jsArrayClass;
     }
 
     if (result == null) return;
 
     result.forEachMember((_, Element member) {
       List<Element> list = interceptedElements.putIfAbsent(
           member.name, () => new List<Element>());
       list.add(member);
     });
 
@@ skipping 266 matching lines @@
     print("Inferred return types:");
     print("----------------------");
     dumpReturnTypes();
     print("");
     print("Inferred field types:");
     print("------------------------");
     fieldTypes.dump();
     print("");
   }
 }