blink: Cleanup core class forward declarations

third_party/WebKit/Source/core/css/CSSStyleDeclaration.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 16 matching lines @@
 #include "wtf/Forward.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class CSSRule;
 class CSSStyleSheet;
 class CSSValue;
 class ExceptionState;
-class MutableStylePropertySet;
 
 class CORE_EXPORT CSSStyleDeclaration
     : public GarbageCollectedFinalized<CSSStyleDeclaration>,
       public ScriptWrappable {
   DEFINE_WRAPPERTYPEINFO();
   WTF_MAKE_NONCOPYABLE(CSSStyleDeclaration);
 
  public:
   virtual ~CSSStyleDeclaration() {}
 
@@ skipping 40 matching lines @@
 
   DECLARE_VIRTUAL_TRACE_WRAPPERS();
 
  protected:
   CSSStyleDeclaration() {}
 };
 
 }  // namespace blink
 
 #endif  // CSSStyleDeclaration_h