Cleanup: Remove unused include headers and forward declarations

Source/core/rendering/compositing/GraphicsLayerUpdater.cpp

 /*
  * 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 13 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/rendering/compositing/GraphicsLayerUpdater.h"
 
 #include "core/html/HTMLMediaElement.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderLayerReflectionInfo.h"
 #include "core/rendering/RenderPart.h"
-#include "core/rendering/RenderView.h"
 #include "core/rendering/compositing/CompositedLayerMapping.h"
 #include "core/rendering/compositing/RenderLayerCompositor.h"
-#include "public/platform/Platform.h"
 
 namespace WebCore {
 
 static bool shouldAppendLayer(const RenderLayer& layer)
 {
     if (!RuntimeEnabledFeatures::overlayFullscreenVideoEnabled())
         return true;
     Node* node = layer.renderer()->node();
     if (node && isHTMLMediaElement(*node) && toHTMLMediaElement(node)->isFullscreen())
         return false;
@@ skipping 138 matching lines @@
     if (layer.hasCompositedLayerMapping())
         layer.compositedLayerMapping()->assertNeedsToUpdateGraphicsLayerBitsCleared();
 
     for (RenderLayer* child = layer.firstChild(); child; child = child->nextSibling())
         assertNeedsToUpdateGraphicsLayerBitsCleared(*child);
 }
 
 #endif
 
 } // namespace WebCore