Clean up forward declarations in Source/core/events

Source/core/events/DOMWindowEventQueue.h

 /*
  * Copyright (C) 2010 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:
  * 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 19 matching lines @@
 #include "core/events/EventQueue.h"
 #include "wtf/HashSet.h"
 #include "wtf/ListHashSet.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/RefCounted.h"
 
 namespace blink {
 
 class Event;
 class DOMWindowEventQueueTimer;
-class Node;
 class ExecutionContext;
 
 #if ENABLE(OILPAN)
 #define DOMWINDOWEVENTQUEUE_BASE_CLASSES public EventQueue
 #else
 #define DOMWINDOWEVENTQUEUE_BASE_CLASSES public RefCounted<DOMWindowEventQueue>, public EventQueue
 #endif
 
 class DOMWindowEventQueue final : DOMWINDOWEVENTQUEUE_BASE_CLASSES {
 public:
@@ skipping 15 matching lines @@
     OwnPtrWillBeMember<DOMWindowEventQueueTimer> m_pendingEventTimer;
     WillBeHeapListHashSet<RefPtrWillBeMember<Event>, 16> m_queuedEvents;
     bool m_isClosed;
 
     friend class DOMWindowEventQueueTimer;
 };
 
 }
 
 #endif // DOMWindowEventQueue_h