Delay construction of StyleResolverState until after style sharing.

Source/core/css/resolver/StyleResolverState.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 27 matching lines @@
 
 namespace blink {
 
 class CSSAnimationUpdate;
 class FontDescription;
 
 class StyleResolverState {
     STACK_ALLOCATED();
     WTF_MAKE_NONCOPYABLE(StyleResolverState);
 public:
+    StyleResolverState(Document&, const ElementResolveContext&, RenderStyle* parentStyle);
     StyleResolverState(Document&, Element*, RenderStyle* parentStyle = 0);
     ~StyleResolverState();
 
     // In FontFaceSet and CanvasRenderingContext2D, we don't have an element to grab the document from.
     // This is why we have to store the document separately.
     Document& document() const { return *m_document; }
     // These are all just pass-through methods to ElementResolveContext.
     Element* element() const { return m_elementContext.element(); }
     const ContainerNode* parentNode() const { return m_elementContext.parentNode(); }
     const RenderStyle* rootElementStyle() const { return m_elementContext.rootElementStyle(); }
@@ skipping 80 matching lines @@
 
 private:
     ElementResolveContext m_elementContext;
     RawPtrWillBeMember<Document> m_document;
 
     // m_style is the primary output for each element's style resolve.
     RefPtr<RenderStyle> m_style;
 
     CSSToLengthConversionData m_cssToLengthConversionData;
 
-    // m_parentStyle is not always just element->parentNode()->style()
-    // so we keep it separate from m_elementContext.
+    // m_parentStyle is not always just ElementResolveContext::parentStyle,
+    // so we keep it separate.
     RefPtr<RenderStyle> m_parentStyle;
 
     OwnPtrWillBeMember<CSSAnimationUpdate> m_animationUpdate;
 
     bool m_applyPropertyToRegularStyle;
     bool m_applyPropertyToVisitedLinkStyle;
 
     FontBuilder m_fontBuilder;
 
     OwnPtr<CachedUAStyle> m_cachedUAStyle;
 
     ElementStyleResources m_elementStyleResources;
     // CSSToStyleMap is a pure-logic class and only contains
     // a back-pointer to this object.
     CSSToStyleMap m_styleMap;
     Vector<AtomicString> m_contentAttrValues;
 };
 
 } // namespace blink
 
 #endif // StyleResolverState_h