Use an AtomicString as key in DocumentOrderedMap

Source/core/dom/DocumentOrderedMap.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef DocumentOrderedMap_h
 #define DocumentOrderedMap_h
 
 #include "platform/heap/Handle.h"
 #include "wtf/Forward.h"
 #include "wtf/HashMap.h"
 #include "wtf/text/AtomicString.h"
+#include "wtf/text/AtomicStringHash.h"
 #include "wtf/text/StringImpl.h"
 
 namespace blink {
 
 class Element;
 class TreeScope;
 
 class DocumentOrderedMap : public NoBaseWillBeGarbageCollected<DocumentOrderedMap> {
 public:
     static PassOwnPtrWillBeRawPtr<DocumentOrderedMap> create();
@@ skipping 23 matching lines @@
         {
         }
 
         void trace(Visitor*);
 
         RawPtrWillBeMember<Element> element;
         unsigned count;
         WillBeHeapVector<RawPtrWillBeMember<Element> > orderedList;
     };
 
-    typedef WillBeHeapHashMap<StringImpl*, OwnPtrWillBeMember<MapEntry> > Map;
+    typedef WillBeHeapHashMap<AtomicString, OwnPtrWillBeMember<MapEntry> > Map;
 
     mutable Map m_map;
 };
 
 inline bool DocumentOrderedMap::contains(const AtomicString& id) const
 {
-    return m_map.contains(id.impl());
+    return m_map.contains(id);
 }
 
 inline bool DocumentOrderedMap::containsMultiple(const AtomicString& id) const
 {
-    Map::const_iterator it = m_map.find(id.impl());
+    Map::const_iterator it = m_map.find(id);
     return it != m_map.end() && it->value->count > 1;
 }
 
 } // namespace blink
 
 #endif // DocumentOrderedMap_h