DOMDataStore should be cleared when shutting down worker threads

Source/bindings/v8/DOMWrapperWorld.h

 /*
  * Copyright (C) 2009 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 45 matching lines @@
 };
 
 // This class represent a collection of DOM wrappers for a specific world.
 class DOMWrapperWorld : public RefCounted<DOMWrapperWorld> {
 public:
     static PassRefPtr<DOMWrapperWorld> create(int worldId = -1, int extensionGroup = -1);
 
     static const int mainWorldExtensionGroup = 0;
     static PassRefPtr<DOMWrapperWorld> ensureIsolatedWorld(int worldId, int extensionGroup);
     ~DOMWrapperWorld();
+    void dispose();
 
     static bool isolatedWorldsExist() { return isolatedWorldCount; }
     static void allWorldsInMainThread(Vector<RefPtr<DOMWrapperWorld> >& worlds);
 
     static DOMWrapperWorld* world(v8::Handle<v8::Context> context)
     {
         ASSERT(contextHasCorrectPrototype(context));
         return V8PerContextData::world(context);
     }
 
@@ skipping 35 matching lines @@
     static bool contextHasCorrectPrototype(v8::Handle<v8::Context>);
 
     const int m_worldId;
     const int m_extensionGroup;
     OwnPtr<DOMDataStore> m_domDataStore;
 };
 
 } // namespace WebCore
 
 #endif // DOMWrapperWorld_h