CSSStyleSheet::insertRule should respect the default namespace

Source/core/css/StyleSheetContents.h

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2008, 2009, 2010, 2012 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 46 matching lines @@
     }
     static PassRefPtrWillBeRawPtr<StyleSheetContents> create(StyleRuleImport* ownerRule, const String& originalURL, const CSSParserContext& context)
     {
         return adoptRefWillBeNoop(new StyleSheetContents(ownerRule, originalURL, context));
     }
 
     ~StyleSheetContents();
 
     const CSSParserContext& parserContext() const { return m_parserContext; }
 
+    const AtomicString& defaultNamespace() { return m_defaultNamespace; }
     const AtomicString& determineNamespace(const AtomicString& prefix);
 
     void parseAuthorStyleSheet(const CSSStyleSheetResource*, const SecurityOrigin*);
     void parseString(const String&);
     void parseStringAtPosition(const String&, const TextPosition&);
 
     bool isCacheable() const;
 
     bool isLoading() const;
 
@@ skipping 90 matching lines @@
     Document* clientSingleOwnerDocument() const;
 
     RawPtrWillBeMember<StyleRuleImport> m_ownerRule;
 
     String m_originalURL;
 
     WillBeHeapVector<RefPtrWillBeMember<StyleRuleImport>> m_importRules;
     WillBeHeapVector<RefPtrWillBeMember<StyleRuleBase>> m_childRules;
     typedef HashMap<AtomicString, AtomicString> PrefixNamespaceURIMap;
     PrefixNamespaceURIMap m_namespaces;
+    AtomicString m_defaultNamespace;
 
     bool m_hasSyntacticallyValidCSSHeader : 1;
     bool m_didLoadErrorOccur : 1;
     bool m_isMutable : 1;
     bool m_isInMemoryCache : 1;
     bool m_hasFontFaceRule : 1;
     bool m_hasMediaQueries : 1;
     bool m_hasSingleOwnerDocument : 1;
 
     CSSParserContext m_parserContext;
 
     WillBeHeapHashSet<RawPtrWillBeWeakMember<CSSStyleSheet>> m_loadingClients;
     WillBeHeapHashSet<RawPtrWillBeWeakMember<CSSStyleSheet>> m_completedClients;
 
     OwnPtrWillBeMember<RuleSet> m_ruleSet;
     String m_sourceMapURL;
 };
 
 } // namespace
 
 #endif