Make Object.observe on the global object functional

src/object-observe.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 31 matching lines @@
 
 InternalObjectHashTable.prototype = {
   get: function(key) {
     return %ObjectHashTableGet(observationState[this.tableName], key);
   },
   set: function(key, value) {
     observationState[this.tableName] =
         %ObjectHashTableSet(observationState[this.tableName], key, value);
   },
   has: function(key) {
-    return %ObjectHashTableHas(observationState[this.tableName], key);
+    return !IS_UNDEFINED(this.get(key));
   }
 };
 
 var observerInfoMap = new InternalObjectHashTable('observerInfoMap');
 var objectInfoMap = new InternalObjectHashTable('objectInfoMap');
 var notifierTargetMap = new InternalObjectHashTable('notifierTargetMap');
 
 function CreateObjectInfo(object) {
   var info = {
     changeObservers: new InternalArray,
@@ skipping 170 matching lines @@
     "getNotifier", ObjectGetNotifier,
     "observe", ObjectObserve,
     "unobserve", ObjectUnobserve
   ));
   InstallFunctions(notifierPrototype, DONT_ENUM, $Array(
     "notify", ObjectNotifierNotify
   ));
 }
 
 SetupObjectObserve();