Clean up forward declarations in Source/core/css

Source/core/css/CSSImageValue.h

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2008, 2012 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 11 matching lines @@
 #define CSSImageValue_h
 
 #include "core/css/CSSValue.h"
 #include "core/fetch/ResourceFetcher.h"
 #include "platform/weborigin/Referrer.h"
 #include "wtf/RefPtr.h"
 
 namespace blink {
 
 class Document;
-class Element;
 class KURL;
 class StyleFetchedImage;
 class StyleImage;
 class RenderObject;
 
 class CSSImageValue : public CSSValue {
 public:
     static PassRefPtrWillBeRawPtr<CSSImageValue> create(const KURL& url, StyleImage* image = 0)
     {
         return adoptRefWillBeNoop(new CSSImageValue(url, url, image));
@@ skipping 40 matching lines @@
     RefPtr<StyleImage> m_image;
     bool m_accessedImage;
     AtomicString m_initiatorName;
 };
 
 DEFINE_CSS_VALUE_TYPE_CASTS(CSSImageValue, isImageValue());
 
 } // namespace blink
 
 #endif // CSSImageValue_h