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

Source/core/dom/shadow/ContentDistributor.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 16 matching lines @@
  * (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 ContentDistributor_h
 #define ContentDistributor_h
 
 #include "core/dom/shadow/SelectRuleFeatureSet.h"
 #include "wtf/Forward.h"
 #include "wtf/HashMap.h"
-#include "wtf/RefCounted.h"
 #include "wtf/Vector.h"
 
 namespace WebCore {
 
 class ContainerNode;
 class Element;
 class InsertionPoint;
 class Node;
 class ShadowRoot;
 
@@ skipping 111 matching lines @@
 
 inline bool ContentDistributor::needsDistribution() const
 {
     // During the invalidation, re-distribution should be supressed.
     return m_validity != Valid && m_validity != Invalidating;
 }
 
 }
 
 #endif