Improve RAII of StyleResolverState.

Source/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 37 matching lines @@
 class CSSStyleSheet;
 class CSSValue;
 class ContainerNode;
 class Document;
 class Element;
 class ElementRuleCollector;
 class Interpolation;
 class MediaQueryEvaluator;
 class RuleData;
 class StyleKeyframe;
+class StyleBasisContext;
 class StylePropertySet;
 class StyleResolverStats;
 class StyleRule;
 class StyleRuleKeyframes;
 class StyleRulePage;
 class ViewportStyleResolver;
 
 class MatchResult;
 
 enum StyleSharingBehavior {
@@ skipping 185 matching lines @@
 
     void matchPageRules(MatchResult&, RuleSet*, bool isLeftPage, bool isFirstPage, const String& pageName);
     void matchPageRulesForList(WillBeHeapVector<RawPtrWillBeMember<StyleRulePage> >& matchedRules, const WillBeHeapVector<RawPtrWillBeMember<StyleRulePage> >&, bool isLeftPage, bool isFirstPage, const String& pageName);
     void collectViewportRules();
 
     bool isLeftPage(int pageIndex) const;
     bool isRightPage(int pageIndex) const { return !isLeftPage(pageIndex); }
     bool isFirstPage(int pageIndex) const;
     String pageName(int pageIndex) const;
 
-    bool pseudoStyleForElementInternal(Element&, const PseudoStyleRequest&, RenderStyle* parentStyle, StyleResolverState&);
+    PassRefPtr<RenderStyle> styleForContext(const StyleBasisContext&);
+    PassRefPtr<RenderStyle> parentStyleForContext(const StyleBasisContext&);
+
+    bool pseudoStyleForElementInternal(const PseudoStyleRequest&, StyleResolverState&, const StyleBasisContext&);
 
     Document& document() { return *m_document; }
 
     // FIXME: This likely belongs on RuleSet.
     typedef WillBeHeapHashMap<StringImpl*, RefPtrWillBeMember<StyleRuleKeyframes> > KeyframesRuleMap;
     KeyframesRuleMap m_keyframesRuleMap;
 
     static RenderStyle* s_styleNotYetAvailable;
 
     void cacheBorderAndBackground();
@@ skipping 30 matching lines @@
     OwnPtr<StyleResolverStats> m_styleResolverStatsTotals;
     unsigned m_styleResolverStatsSequence;
 
     // Use only for Internals::updateStyleAndReturnAffectedElementCount.
     unsigned m_accessCount;
 };
 
 } // namespace blink
 
 #endif // StyleResolver_h