Change shadow style's scope from Shadow Host to Shadow Root

Source/core/css/resolver/ScopedStyleResolver.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.
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 102 matching lines @@
 }
 
 void ScopedStyleResolver::collectMatchingAuthorRules(ElementRuleCollector& collector, bool includeEmptyRules, bool applyAuthorStyles, CascadeScope cascadeScope, CascadeOrder cascadeOrder)
 {
     const ContainerNode* scopingNode = &m_scopingNode;
     unsigned behaviorAtBoundary = SelectorChecker::DoesNotCrossBoundary;
 
     if (!applyAuthorStyles)
         behaviorAtBoundary |= SelectorChecker::ScopeContainsLastMatchedElement;
 
-    if (m_scopingNode.isShadowRoot()) {
-        scopingNode = toShadowRoot(m_scopingNode).host();
-        behaviorAtBoundary |= SelectorChecker::ScopeIsShadowHost;
-    }
+    if (m_scopingNode.isShadowRoot())
+        behaviorAtBoundary |= SelectorChecker::ScopeIsShadowRoot;
 
     RuleRange ruleRange = collector.matchedResult().ranges.authorRuleRange();
     for (size_t i = 0; i < m_authorStyleSheets.size(); ++i) {
         MatchRequest matchRequest(&m_authorStyleSheets[i]->contents()->ruleSet(), includeEmptyRules, scopingNode, m_authorStyleSheets[i], applyAuthorStyles, i);
         collector.collectMatchingRules(matchRequest, ruleRange, static_cast<SelectorChecker::BehaviorAtBoundary>(behaviorAtBoundary), cascadeScope, cascadeOrder);
     }
 }
 
 void ScopedStyleResolver::matchPageRules(PageRuleCollector& collector)
 {
     // Only consider the global author RuleSet for @page rules, as per the HTML5 spec.
     ASSERT(m_scopingNode.isDocumentNode());
     for (size_t i = 0; i < m_authorStyleSheets.size(); ++i)
         collector.matchPageRules(&m_authorStyleSheets[i]->contents()->ruleSet());
 }
 
 void ScopedStyleResolver::collectViewportRulesTo(StyleResolver* resolver) const
 {
     if (!m_scopingNode.isDocumentNode())
         return;
     for (size_t i = 0; i < m_authorStyleSheets.size(); ++i)
         resolver->viewportStyleResolver()->collectViewportRules(&m_authorStyleSheets[i]->contents()->ruleSet(), ViewportStyleResolver::AuthorOrigin);
 }
 
 } // namespace WebCore