Clear StyleResolverState after each resolve.

Source/core/css/resolver/StyleResolverState.cpp

 /*
  * 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 16 matching lines @@
 #include "core/dom/NodeRenderStyle.h"
 #include "core/dom/NodeRenderingContext.h"
 #include "core/dom/VisitedLinkState.h"
 #include "core/page/Page.h"
 
 namespace WebCore {
 
 void StyleResolverState::clear()
 {
     m_element = 0;
+    m_style = 0;
     m_styledElement = 0;
     m_parentStyle = 0;
     m_parentNode = 0;
     m_regionForStyling = 0;
     m_elementStyleResources.clear();
 }
 
+PassRefPtr<RenderStyle> StyleResolverState::takeStyleAndClear()
+{
+    RefPtr<RenderStyle> result = takeStyle();
+    clear();
+    return result.release();
+}
+
 void StyleResolverState::initElement(Element* element)
 {
     if (m_element == element)
         return;
 
     m_element = element;
     m_styledElement = element && element->isStyledElement() ? element : 0;
     m_elementLinkState = element ? element->document()->visitedLinkState()->determineLinkState(element) : NotInsideLink;
 
     if (!element || element != element->document()->documentElement())
@@ skipping 28 matching lines @@
 
     m_style = 0;
     m_elementStyleResources.clear();
     m_fontDirty = false;
 
     if (Page* page = document->page())
         m_elementStyleResources.setDeviceScaleFactor(page->deviceScaleFactor());
 }
 
 } // namespace WebCore