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

Source/core/css/CSSLineBoxContainValue.h

 /*
  * Copyright (C) 2011 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 10 matching lines @@
  * 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 CSSLineBoxContainValue_h
 #define CSSLineBoxContainValue_h
 
 #include "core/css/CSSValue.h"
 #include <wtf/PassRefPtr.h>
-#include <wtf/RefPtr.h>
 
 namespace WebCore {
 
 class CSSPrimitiveValue;
 
 enum LineBoxContainFlags { LineBoxContainNone = 0x0, LineBoxContainBlock = 0x1, LineBoxContainInline = 0x2, LineBoxContainFont = 0x4, LineBoxContainGlyphs = 0x8,
                            LineBoxContainReplaced = 0x10, LineBoxContainInlineBox = 0x20 };
 typedef unsigned LineBoxContain;
 
 // Used for text-CSSLineBoxContain and box-CSSLineBoxContain
@@ skipping 13 matching lines @@
 private:
     LineBoxContain m_value;
 
 private:
     CSSLineBoxContainValue(LineBoxContain);
 };
 
 } // namespace
 
 #endif