Simplify lifecycle notifiers and observers.

Source/core/frame/LocalDOMWindow.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 12 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef LocalDOMWindow_h
 #define LocalDOMWindow_h
 
 #include "core/events/EventTarget.h"
 #include "core/frame/DOMWindow.h"
 #include "core/frame/DOMWindowLifecycleNotifier.h"
+#include "core/frame/DOMWindowLifecycleObserver.h"
 #include "core/frame/FrameDestructionObserver.h"
 #include "core/frame/LocalFrame.h"
 #include "platform/Supplementable.h"
 #include "platform/heap/Handle.h"
 
 #include "wtf/Assertions.h"
 #include "wtf/Forward.h"
 
 namespace blink {
 
@@ skipping 256 matching lines @@
 }
 
 inline String LocalDOMWindow::defaultStatus() const
 {
     return m_defaultStatus;
 }
 
 } // namespace blink
 
 #endif // LocalDOMWindow_h