Change RefPtr<DOMWrapperWorld> that causes reference cycles to DOMWrapperWorld*

Source/bindings/v8/WorkerScriptController.cpp

 /*
  * Copyright (C) 2009, 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 195 matching lines @@
 void WorkerScriptController::evaluate(const ScriptSourceCode& sourceCode, RefPtr<ErrorEvent>* errorEvent)
 {
     if (isExecutionForbidden())
         return;
 
     WorkerGlobalScopeExecutionState state;
     evaluate(sourceCode.source(), sourceCode.url().string(), sourceCode.startPosition(), &state);
     if (state.hadException) {
         if (errorEvent) {
             *errorEvent = m_workerGlobalScope.shouldSanitizeScriptError(state.sourceURL, NotSharableCrossOrigin) ?
-                ErrorEvent::createSanitizedError(nullptr) : ErrorEvent::create(state.errorMessage, state.sourceURL, state.lineNumber, state.columnNumber, nullptr);
+                ErrorEvent::createSanitizedError(0) : ErrorEvent::create(state.errorMessage, state.sourceURL, state.lineNumber, state.columnNumber, 0);
             V8ErrorHandler::storeExceptionOnErrorEventWrapper(errorEvent->get(), state.exception.v8Value(), m_isolate);
         } else {
             ASSERT(!m_workerGlobalScope.shouldSanitizeScriptError(state.sourceURL, NotSharableCrossOrigin));
-            RefPtr<ErrorEvent> event = m_errorEventFromImportedScript ? m_errorEventFromImportedScript.release() : ErrorEvent::create(state.errorMessage, state.sourceURL, state.lineNumber, state.columnNumber, nullptr);
+            RefPtr<ErrorEvent> event = m_errorEventFromImportedScript ? m_errorEventFromImportedScript.release() : ErrorEvent::create(state.errorMessage, state.sourceURL, state.lineNumber, state.columnNumber, 0);
             m_workerGlobalScope.reportException(event, nullptr, NotSharableCrossOrigin);
         }
     }
 }
 
 void WorkerScriptController::scheduleExecutionTermination()
 {
     // The mutex provides a memory barrier to ensure that once
     // termination is scheduled, isExecutionTerminating will
     // accurately reflect that state when called from another thread.
@@ skipping 42 matching lines @@
     v8::Handle<v8::Context> context = isolate->GetCurrentContext();
     v8::Handle<v8::Object> global = V8WorkerGlobalScope::findInstanceInPrototypeChain(context->Global(), isolate);
     // Return 0 if the current executing context is not the worker context.
     if (global.IsEmpty())
         return 0;
     WorkerGlobalScope* workerGlobalScope = V8WorkerGlobalScope::toNative(global);
     return workerGlobalScope->script();
 }
 
 } // namespace WebCore