Remove duplicated headers from core/

Source/core/dom/ElementData.cpp

 /*
  * Copyright (C) 2013 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:
  *
  *     * 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.
  */
 
 #include "config.h"
 #include "core/dom/ElementData.h"
 
 #include "core/css/StylePropertySet.h"
 #include "core/dom/Attr.h"
 #include "core/dom/QualifiedName.h"
 #include "wtf/Vector.h"
-#include "wtf/text/AtomicString.h"
 
 namespace WebCore {
 
 struct SameSizeAsElementData : public RefCounted<SameSizeAsElementData> {
     unsigned bitfield;
     void* refPtrs[3];
 };
 
 COMPILE_ASSERT(sizeof(ElementData) == sizeof(SameSizeAsElementData), element_attribute_data_should_stay_small);
 
@@ skipping 166 matching lines @@
 Attribute* UniqueElementData::getAttributeItem(const QualifiedName& name)
 {
     for (unsigned i = 0; i < length(); ++i) {
         if (m_attributeVector.at(i).name().matches(name))
             return &m_attributeVector.at(i);
     }
     return 0;
 }
 
 } // namespace WebCore