Clean up forward declarations in Source/core/editing

Source/core/editing/FrameSelection.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple 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 25 matching lines @@
 #include "platform/geometry/LayoutRect.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Noncopyable.h"
 
 namespace blink {
 
 class CharacterData;
 class LocalFrame;
 class GraphicsContext;
 class HTMLFormElement;
-class MutableStylePropertySet;
-class RenderObject;
-class RenderView;
-class Settings;
 class Text;
 class VisiblePosition;
 
 enum EUserTriggered { NotUserTriggered = 0, UserTriggered = 1 };
 
 enum RevealExtentOption {
     RevealExtent,
     DoNotRevealExtent
 };
 
@@ skipping 250 matching lines @@
 }
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showTree(const blink::FrameSelection&);
 void showTree(const blink::FrameSelection*);
 #endif
 
 #endif // FrameSelection_h