dart2js: Merge intercepted names map.

sdk/lib/_internal/compiler/js_lib/js_helper.dart

 // Copyright (c) 2013, 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.
 
 library _js_helper;
 
 import 'dart:_js_embedded_names' show
     ALL_CLASSES,
     GET_ISOLATE_TAG,
     INTERCEPTED_NAMES,
@@ skipping 206 matching lines @@
           _arguments[namedArgumentsStartIndex + i];
     }
     return map;
   }
 
   _getCachedInvocation(Object object) {
     var interceptor = getInterceptor(object);
     var receiver = object;
     var name = _internalName;
     var arguments = _arguments;
-    var embeddedInterceptedNames = JS_EMBEDDED_GLOBAL('', INTERCEPTED_NAMES);
-    // TODO(ngeoffray): If this functionality ever become performance
-    // critical, we might want to dynamically change [interceptedNames]
-    // to be a JavaScript object with intercepted names as property
-    // instead of a JavaScript array.
-    // TODO(floitsch): we already add stubs (tear-off getters) as properties
-    // in the embedded global interceptedNames.
-    // Finish the transition and always use the object as hashtable.
+    var interceptedNames = JS_EMBEDDED_GLOBAL('', INTERCEPTED_NAMES);
     bool isIntercepted =
-        JS("bool",
-            'Object.prototype.hasOwnProperty.call(#, #) || #.indexOf(#) !== -1',
-            embeddedInterceptedNames, name, interceptedNames, name);
+        JS("bool", 'Object.prototype.hasOwnProperty.call(#, #)',
+            interceptedNames, name);
     if (isIntercepted) {
       receiver = interceptor;
       if (JS('bool', '# === #', object, interceptor)) {
         interceptor = null;
       }
     } else {
       interceptor = null;
     }
     bool isCatchAll = false;
     var method = JS('var', '#[#]', receiver, name);
@@ skipping 3187 matching lines @@
   throw new MainError("No top-level function named 'main'.");
 }
 
 void badMain() {
   throw new MainError("'main' is not a function.");
 }
 
 void mainHasTooManyParameters() {
   throw new MainError("'main' expects too many parameters.");
 }