Remove unused includes from core/accessibility, core/css and core/dom

Source/core/dom/MutationObserver.h

 /*
  * Copyright (C) 2011 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 14 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef MutationObserver_h
 #define MutationObserver_h
 
 #include "bindings/v8/ScriptWrappable.h"
-#include "wtf/HashMap.h"
 #include "wtf/HashSet.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/RefPtr.h"
-#include "wtf/text/AtomicString.h"
-#include "wtf/text/AtomicStringHash.h"
 
 namespace WebCore {
 
 class Dictionary;
 class MutationCallback;
 class MutationObserverRegistration;
 class MutationRecord;
 class Node;
 
 typedef int ExceptionCode;
@@ skipping 47 matching lines @@
 
     RefPtr<MutationCallback> m_callback;
     Vector<RefPtr<MutationRecord> > m_records;
     HashSet<MutationObserverRegistration*> m_registrations;
     unsigned m_priority;
 };
 
 }
 
 #endif // MutationObserver_h