Remove StyleEngine.h include from RenderObject.h

Source/core/html/track/vtt/VTTRegion.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/html/track/vtt/VTTRegion.h"
 
 #include "bindings/core/v8/ExceptionMessages.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/dom/ClientRect.h"
 #include "core/dom/DOMTokenList.h"
+#include "core/dom/ElementTraversal.h"
 #include "core/html/HTMLDivElement.h"
 #include "core/html/track/vtt/VTTParser.h"
 #include "core/html/track/vtt/VTTScanner.h"
 #include "core/rendering/RenderInline.h"
 #include "core/rendering/RenderObject.h"
 #include "platform/Logging.h"
 #include "wtf/MathExtras.h"
 #include "wtf/text/StringBuilder.h"
 
 namespace WebCore {
@@ skipping 420 matching lines @@
 }
 
 void VTTRegion::trace(Visitor* visitor)
 {
     visitor->trace(m_cueContainer);
     visitor->trace(m_regionDisplayTree);
     visitor->trace(m_track);
 }
 
 } // namespace WebCore