Revert of Make DOMWrapperWorld::current() return a reference instead of a pointer

Source/bindings/v8/V8PerContextData.h

 /*
  * Copyright (C) 2012 Google Inc. 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
@@ skipping 49 matching lines @@
 };
 
 class V8PerContextData {
 public:
     static PassOwnPtr<V8PerContextData> create(v8::Handle<v8::Context> context, PassRefPtr<DOMWrapperWorld> world)
     {
         return adoptPtr(new V8PerContextData(context, world));
     }
 
     static V8PerContextData* from(v8::Handle<v8::Context>);
-    static DOMWrapperWorld& world(v8::Handle<v8::Context>);
+    static DOMWrapperWorld* world(v8::Handle<v8::Context>);
 
     ~V8PerContextData();
 
     v8::Handle<v8::Context> context() { return m_context.newLocal(m_isolate); }
 
     // To create JS Wrapper objects, we create a cache of a 'boiler plate'
     // object, and then simply Clone that object each time we need a new one.
     // This is faster than going through the full object creation process.
     v8::Local<v8::Object> createWrapperFromCache(const WrapperTypeInfo* type)
     {
@@ skipping 51 matching lines @@
 
 class V8PerContextDebugData {
 public:
     static bool setContextDebugData(v8::Handle<v8::Context>, const char* worldName, int debugId);
     static int contextDebugId(v8::Handle<v8::Context>);
 };
 
 } // namespace WebCore
 
 #endif // V8PerContextData_h