Remove unnecessary includes from dom.

third_party/WebKit/Source/core/dom/shadow/ShadowRootRareData.h

 /*
  * 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 15 matching lines @@
  * 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 ShadowRootRareData_h
 #define ShadowRootRareData_h
 
 #include "core/dom/shadow/InsertionPoint.h"
 #include "core/html/HTMLSlotElement.h"
-#include "wtf/RefPtr.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 class ShadowRootRareData : public GarbageCollected<ShadowRootRareData> {
 public:
     ShadowRootRareData()
         : m_descendantShadowElementCount(0)
         , m_descendantContentElementCount(0)
         , m_childShadowRootCount(0)
@@ skipping 75 matching lines @@
         ASSERT(m_descendantContentElementCount > 0);
         --m_descendantContentElementCount;
     } else {
         ASSERT_NOT_REACHED();
     }
 }
 
 } // namespace blink
 
 #endif