Cleanup: Remove unused include headers and forward declarations

Source/core/rendering/compositing/GraphicsLayerUpdater.h

 /*
  * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2014 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:
  * 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
@@ skipping 10 matching lines @@
  * 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 GraphicsLayerUpdater_h
 #define GraphicsLayerUpdater_h
 
 #include "platform/graphics/GraphicsLayer.h"
-#include "wtf/Vector.h"
 
 namespace WebCore {
 
 class RenderLayer;
-class RenderPart;
-class RenderView;
 
 class GraphicsLayerUpdater {
     class UpdateContext {
     public:
         UpdateContext()
             : m_compositingStackingContext(0)
             , m_compositingAncestor(0)
         {
         }
 
@@ skipping 23 matching lines @@
     static void assertNeedsToUpdateGraphicsLayerBitsCleared(RenderLayer&);
 #endif
 
 private:
     bool m_needsRebuildTree;
 };
 
 } // namespace WebCore
 
 #endif // GraphicsLayerUpdater_h