Clean up forward declarations in Source/core/events

Source/core/events/KeyboardEvent.h

 /*
  * Copyright (C) 2001 Peter Kelly (pmk@post.com)
  * Copyright (C) 2001 Tobias Anton (anton@stud.fbi.fh-darmstadt.de)
  * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 12 matching lines @@
 
 #ifndef KeyboardEvent_h
 #define KeyboardEvent_h
 
 #include "core/events/EventDispatchMediator.h"
 #include "core/events/UIEventWithKeyState.h"
 
 namespace blink {
 
 class EventDispatcher;
-class Node;
 class PlatformKeyboardEvent;
 
 struct KeyboardEventInit : public UIEventInit {
     KeyboardEventInit();
 
     String keyIdentifier;
     unsigned location;
     bool ctrlKey;
     bool altKey;
     bool shiftKey;
@@ skipping 77 matching lines @@
 private:
     explicit KeyboardEventDispatchMediator(PassRefPtrWillBeRawPtr<KeyboardEvent>);
     virtual bool dispatchEvent(EventDispatcher*) const override;
 };
 
 DEFINE_EVENT_TYPE_CASTS(KeyboardEvent);
 
 } // namespace blink
 
 #endif // KeyboardEvent_h