Remove the CSSOM.

sky/engine/core/css/resolver/StyleResolver.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 25 matching lines @@
 #include "sky/engine/wtf/ListHashSet.h"
 #include "sky/engine/wtf/RefPtr.h"
 #include "sky/engine/wtf/Vector.h"
 
 namespace blink {
 
 class AnimatableValue;
 class AnimationTimeline;
 class CSSAnimationUpdate;
 class CSSFontSelector;
-class CSSRuleList;
 class CSSSelector;
 class CSSStyleSheet;
 class CSSValue;
 class ContainerNode;
 class Document;
 class Element;
 class ElementRuleCollector;
 class Interpolation;
 class KeyframeList;
 class KeyframeValue;
@@ skipping 192 matching lines @@
     OwnPtr<StyleResolverStats> m_styleResolverStatsTotals;
     unsigned m_styleResolverStatsSequence;
 
     // Use only for Internals::updateStyleAndReturnAffectedElementCount.
     unsigned m_accessCount;
 };
 
 } // namespace blink
 
 #endif  // SKY_ENGINE_CORE_CSS_RESOLVER_STYLERESOLVER_H_