Clean up forward declarations in Source/core/css

Source/core/css/RuleFeature.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 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 14 matching lines @@
 #include "core/css/CSSSelector.h"
 #include "core/css/invalidation/StyleInvalidator.h"
 #include "wtf/Forward.h"
 #include "wtf/HashSet.h"
 #include "wtf/text/AtomicStringHash.h"
 
 namespace blink {
 
 class CSSSelectorList;
 class DescendantInvalidationSet;
-class Document;
-class Node;
 class QualifiedName;
 class RuleData;
-class ShadowRoot;
 class SpaceSplitString;
 class StyleRule;
 
 struct RuleFeature {
     ALLOW_ONLY_INLINE_ALLOCATION();
 public:
     RuleFeature(StyleRule* rule, unsigned selectorIndex, bool hasDocumentSecurityOrigin);
 
     void trace(Visitor*);
 
@@ skipping 134 matching lines @@
 
 template <> struct VectorTraits<blink::RuleFeature> : VectorTraitsBase<blink::RuleFeature> {
     static const bool needsDestruction = false;
     static const bool canInitializeWithMemset = true;
     static const bool canMoveWithMemcpy = true;
 };
 
 } // namespace WTF
 
 #endif // RuleFeature_h