Clear StyleResolverState after each resolve.

Source/core/css/resolver/StyleResolverState.h

Index: Source/core/css/resolver/StyleResolverState.h
diff --git a/Source/core/css/resolver/StyleResolverState.h b/Source/core/css/resolver/StyleResolverState.h
index b8fce1c06eea82f7852039964551e7588a03e575..047afe9b3ac65d76c4ad8ffad28ab979ceb3c36d 100644
--- a/Source/core/css/resolver/StyleResolverState.h
+++ b/Source/core/css/resolver/StyleResolverState.h
@@ -60,8 +60,14 @@ public:
     , 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; }
@@ -142,6 +148,9 @@ public:
     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;