DOMDataStore should be cleared when shutting down worker threads

Source/bindings/v8/V8WindowShell.cpp

 /*
  * Copyright (C) 2008, 2009, 2011 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 268 matching lines @@
         if (!m_frame->loader().client()->allowScriptExtension(extensions[i]->name(), extensionGroup, worldId))
             continue;
 
         extensionNames[index++] = extensions[i]->name();
     }
     v8::ExtensionConfiguration extensionConfiguration(index, extensionNames.get());
 
     v8::Handle<v8::Context> context = v8::Context::New(m_isolate, &extensionConfiguration, globalTemplate, m_global.newLocal(m_isolate));
     if (context.IsEmpty())
         return;
-    m_perContextData = V8PerContextData::create(context, m_world.get());
+    m_perContextData = V8PerContextData::create(context, m_world);
 
     double contextCreationDurationInMilliseconds = (currentTime() - contextCreationStartInSeconds) * 1000;
     const char* histogramName = "WebCore.V8WindowShell.createContext.MainWorld";
     if (!m_world->isMainWorld())
         histogramName = "WebCore.V8WindowShell.createContext.IsolatedWorld";
     blink::Platform::current()->histogramCustomCounts(histogramName, contextCreationDurationInMilliseconds, 0, 10000, 50);
 }
 
 static v8::Handle<v8::Object> toInnerGlobalObject(v8::Handle<v8::Context> context)
 {
@@ skipping 206 matching lines @@
     if (!isMainThread())
         return true;
     // We're initializing the context, so it is not yet in a status where we can
     // validate the context.
     if (contextBeingInitialized)
         return true;
     return !!toDOMWindow(context);
 }
 
 } // WebCore