Have LifecycleContext::lifecycleNotifier() return a reference

Source/core/frame/DOMWindow.h

 /*
  * Copyright (C) 2006, 2007, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 364 matching lines @@
         // frame), we would like to zero out m_frame to avoid being confused
         // by the document that is currently active in m_frame.
         bool isCurrentlyDisplayedInFrame() const;
 
         void willDetachDocumentFromFrame();
         DOMWindow* anonymousIndexedGetter(uint32_t);
 
         bool isInsecureScriptAccess(DOMWindow* activeWindow, const String& urlString);
 
     protected:
-        DOMWindowLifecycleNotifier* lifecycleNotifier();
+        DOMWindowLifecycleNotifier& lifecycleNotifier();
 
     private:
         explicit DOMWindow(Frame*);
 
         Page* page();
 
         virtual PassOwnPtr<LifecycleNotifier<DOMWindow> > createLifecycleNotifier() OVERRIDE;
 
         virtual void frameDestroyed() OVERRIDE;
         virtual void willDetachPage() OVERRIDE;
@@ skipping 39 matching lines @@
     }
 
     inline String DOMWindow::defaultStatus() const
     {
         return m_defaultStatus;
     }
 
 } // namespace WebCore
 
 #endif // DOMWindow_h