Clean up forward declarations in Source/core/frame

Source/core/frame/FrameView.h

 /*
    Copyright (C) 1997 Martin Jones (mjones@kde.org)
              (C) 1998 Waldo Bastian (bastian@kde.org)
              (C) 1998, 1999 Torben Weis (weis@kde.org)
              (C) 1999 Lars Knoll (knoll@kde.org)
              (C) 1999 Antti Koivisto (koivisto@kde.org)
    Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 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
@@ skipping 33 matching lines @@
 class FloatSize;
 class HTMLFrameOwnerElement;
 class LocalFrame;
 class KURL;
 class Node;
 class Page;
 class RenderBox;
 class RenderEmbeddedObject;
 class RenderObject;
 class RenderScrollbarPart;
-class RenderStyle;
 class RenderView;
 class RenderWidget;
 
 typedef unsigned long long DOMTimeStamp;
 
 class FrameView FINAL : public ScrollView {
 public:
     friend class RenderView;
     friend class Internals;
 
@@ skipping 474 matching lines @@
         m_view->setCanInvalidatePaintDuringPerformLayout(m_originalValue);
     }
 private:
     FrameView* m_view;
     bool m_originalValue;
 };
 
 } // namespace blink
 
 #endif // FrameView_h