cc: Cleanup class/struct forward declarations

cc/layers/nine_patch_layer.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_LAYERS_NINE_PATCH_LAYER_H_
 #define CC_LAYERS_NINE_PATCH_LAYER_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "cc/base/cc_export.h"
 #include "cc/layers/layer.h"
 #include "cc/layers/ui_resource_layer.h"
 #include "cc/resources/ui_resource_client.h"
 #include "ui/gfx/geometry/rect.h"
 
 namespace cc {
 
-class LayerTreeHost;
-class ScopedUIResource;
-
 class CC_EXPORT NinePatchLayer : public UIResourceLayer {
  public:
   static scoped_refptr<NinePatchLayer> Create();
 
   void PushPropertiesTo(LayerImpl* layer) override;
 
   // |border| is the space around the center rectangular region in layer space
   // (known as aperture in image space).  |border.x()| and |border.y()| are the
   // size of the left and top boundary, respectively.
   // |border.width()-border.x()| and |border.height()-border.y()| are the size
@@ skipping 31 matching lines @@
   // The occluded region in layer space set by SetLayerOcclusion. It is
   // usually larger than |image_aperture_|.
   gfx::Rect layer_occlusion_;
 
   DISALLOW_COPY_AND_ASSIGN(NinePatchLayer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_NINE_PATCH_LAYER_H_