Remove parent() concept from ScopedStyleResolver.

sky/engine/core/css/resolver/ScopedStyleResolver.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.
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 36 matching lines @@
     WTF_MAKE_FAST_ALLOCATED;
 public:
     static PassOwnPtr<ScopedStyleResolver> create(TreeScope& scope)
     {
         return adoptPtr(new ScopedStyleResolver(scope));
     }
 
     static TreeScope* treeScopeFor(Document&, const CSSStyleSheet*);
 
     const TreeScope& treeScope() const { return *m_scope; }
-    ScopedStyleResolver* parent() const;
 
 public:
     const StyleRuleKeyframes* keyframeStylesForAnimation(const StringImpl* animationName);
     void addKeyframeStyle(PassRefPtr<StyleRuleKeyframes>);
 
     void collectMatchingAuthorRules(ElementRuleCollector&, bool includeEmptyRules, bool applyAuthorStyles, CascadeScope, CascadeOrder = ignoreCascadeOrder);
     void addRulesFromSheet(CSSStyleSheet*, const MediaQueryEvaluator&, StyleResolver*);
     void collectFeaturesTo(RuleFeatureSet&, HashSet<const StyleSheetContents*>& visitedSharedStyleSheetContents) const;
     void resetAuthorStyle();
 
 private:
     explicit ScopedStyleResolver(TreeScope& scope)
         : m_scope(scope)
     {
     }
 
     RawPtr<TreeScope> m_scope;
 
     Vector<RawPtr<CSSStyleSheet> > m_authorStyleSheets;
 
     typedef HashMap<const StringImpl*, RefPtr<StyleRuleKeyframes> > KeyframesRuleMap;
     KeyframesRuleMap m_keyframesRuleMap;
 };
 
 } // namespace blink
 
 #endif  // SKY_ENGINE_CORE_CSS_RESOLVER_SCOPEDSTYLERESOLVER_H_