Clear StyleResolverState after each resolve.

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 42 matching lines @@
     , m_elementLinkState(NotInsideLink)
     , m_distributedToInsertionPoint(false)
     , m_elementAffectedByClassRules(false)
     , m_applyPropertyToRegularStyle(true)
     , m_applyPropertyToVisitedLinkStyle(false)
     , m_lineHeightValue(0)
     , m_fontDirty(false)
     , m_styleMap(*this, m_elementStyleResources)
     { }
 
-    void initForStyleResolve(Document*, Element*, int childIndex = 0, RenderStyle* parentStyle = 0, RenderRegion* regionForStyling = 0);
-    void clear();
+public:
+    class ScopedStyleResolution {

[dglazkov, 2013/07/12 16:45:47]

Can we un-nest this?

[Jeffrey Yasskin, 2013/07/12 19:41:28]

Yep, done.

+    public:
+        ScopedStyleResolution(StyleResolverState*, Document*, Element*, int childIndex = 0, RenderStyle* parentStyle = 0, RenderRegion* regionForStyling = 0);
+        ~ScopedStyleResolution();
+    private:
+        StyleResolverState* m_state;
+    };
 
     Document* document() const { return m_element->document(); }
     Element* element() const { return m_element; }
     int childIndex() const { return m_childIndex; }
     Element* styledElement() const { return m_styledElement; }
     void setStyle(PassRefPtr<RenderStyle> style) { m_style = style; }
     RenderStyle* style() const { return m_style.get(); }
     PassRefPtr<RenderStyle> takeStyle() { return m_style.release(); }
 
     const ContainerNode* parentNode() const { return m_parentNode; }
@@ skipping 60 matching lines @@
     // of each individual length value in the render style / tree. CSSPrimitiveValue::computeLength*()
     // multiplies each resolved length with the zoom multiplier - so for SVG we need to disable that.
     // Though all CSS values that can be applied to outermost <svg> elements (width/height/border/padding...)
     // need to respect the scaling. RenderBox (the parent class of RenderSVGRoot) grabs values like
     // width/height/border/padding/... from the RenderStyle -> for SVG these values would never scale,
     // if we'd pass a 1.0 zoom factor everyhwere. So we only pass a zoom factor of 1.0 for specific
     // properties that are NOT allowed to scale within a zoomed SVG document (letter/word-spacing/font-size).
     bool useSVGZoomRules() const { return m_element && m_element->isSVGElement(); }
 
 private:
+    void initForStyleResolve(Document*, Element*, int childIndex = 0, RenderStyle* parentStyle = 0, RenderRegion* regionForStyling = 0);
+    void clear();
+
     void initElement(Element*, int childIndex);
 
     Element* m_element;
     int m_childIndex;
     RefPtr<RenderStyle> m_style;
     Element* m_styledElement;
     ContainerNode* m_parentNode;
     RefPtr<RenderStyle> m_parentStyle;
     RenderStyle* m_rootElementStyle;
 
@@ skipping 15 matching lines @@
     CachedUAStyle m_cachedUAStyle;
     ElementStyleResources m_elementStyleResources;
     // CSSToStyleMap is a pure-logic class and only contains
     // a back-pointer to this object.
     CSSToStyleMap m_styleMap;
 };
 
 } // namespace WebCore
 
 #endif // StyleResolverState_h