Oilpan: Move [WillBeGarbageCollected] from Node to EventTarget.

Source/modules/serviceworkers/ServiceWorkerContainer.h

 /*
  * Copyright (C) 2013 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 @@
     public blink::WebServiceWorkerProviderClient {
 public:
     static PassRefPtr<ServiceWorkerContainer> create(ExecutionContext*);
     ~ServiceWorkerContainer();
 
     void detachClient();
 
     ScriptPromise registerServiceWorker(ScriptState*, const String& pattern, const Dictionary&);
     ScriptPromise unregisterServiceWorker(ScriptState*, const String& scope = String());
 
-    PassRefPtr<ServiceWorker> controller() { return m_controller; }
+    PassRefPtrWillBeRawPtr<ServiceWorker> controller() { return m_controller.get(); }
 
     // WebServiceWorkerProviderClient overrides.
     virtual void setController(blink::WebServiceWorker*) OVERRIDE;
     virtual void dispatchMessageEvent(const blink::WebString& message, const blink::WebMessagePortChannelArray&) OVERRIDE;
 
     // FIXME: Delete this when the embedder switches to setController.
     virtual void setCurrentServiceWorker(blink::WebServiceWorker*) OVERRIDE;
 
 private:
     explicit ServiceWorkerContainer(ExecutionContext*);
 
     blink::WebServiceWorkerProvider* m_provider;
     RefPtr<ServiceWorker> m_controller;
 };
 
 } // namespace WebCore
 
 #endif // ServiceWorkerContainer_h