Avoid always style recalc when removing stylesheets.

Source/core/css/resolver/StyleResolver.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 193 matching lines @@
     collectFeatures();
 
     if (document().renderer() && document().renderer()->style())
         document().renderer()->style()->font().update(fontSelector());
 
     collectViewportRules();
 }
 
 void StyleResolver::resetAuthorStyle(const ContainerNode* scopingNode)
 {
-    ScopedStyleResolver* resolver = scopingNode ? m_styleTree.scopedStyleResolverFor(*scopingNode) : m_styleTree.scopedStyleResolverForDocument();
+    // FIXME: When chanking scoped attribute, scopingNode's hasScopedHTMLStyleChild has been already modified.

[eseidel, 2013/10/17 15:53:11]

"changing" I think.

+    // So we cannot use hasScopedHTMLStyleChild flag here.
+    ScopedStyleResolver* resolver = scopingNode ? m_styleTree.lookupScopedStyleResolverFor(scopingNode) : m_styleTree.scopedStyleResolverForDocument();
     if (!resolver)
         return;
 
     m_ruleSets.shadowDistributedRules().reset(scopingNode);
 
     resolver->resetAuthorStyle();
     if (!scopingNode)
         return;
 
     if (scopingNode->isShadowRoot())
@@ skipping 1409 matching lines @@
         m_matchedPropertiesSearches, m_matchedPropertiesHit, m_matchedPropertiesSharedInheritedHit, m_matchedPropertiesToCache, m_matchedPropertiesEnteredIntoCache);
 
     fprintf(stderr, "Total:\n");
     printStyleStats(m_totalSearches, m_totalElementsEligibleForSharing, m_totalStylesShared, m_totalSearchFoundSiblingForSharing, m_totalSearchesMissedSharing,
         m_totalMatchedPropertiesSearches, m_totalMatchedPropertiesHit, m_totalMatchedPropertiesSharedInheritedHit, m_totalMatchedPropertiesToCache, m_totalMatchedPropertiesEnteredIntoCache);
     fprintf(stderr, "--------------------------------------------------------------------------------\n");
 }
 #endif
 
 } // namespace WebCore