Move LayerSorter to exist locally only in layer_tree_host_common

cc/layer_impl.h

 // Copyright 2011 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_LAYER_IMPL_H_
 #define CC_LAYER_IMPL_H_
 
 #include <public/WebFilterOperations.h>
 #include <string>
 
@@ skipping 11 matching lines @@
 #include "cc/shared_quad_state.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkImageFilter.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/rect_f.h"
 #include "ui/gfx/transform.h"
 
 namespace cc {
 
-class LayerSorter;
 class LayerTreeHostImpl;
 class QuadSink;
 class Renderer;
 class ScrollbarAnimationController;
 class ScrollbarLayerImpl;
 class Layer;
 
 struct AppendQuadsData;
 
 class CC_EXPORT LayerImpl : public LayerAnimationControllerClient {
@@ skipping 349 matching lines @@
     // Manages scrollbars for this layer
     scoped_ptr<ScrollbarAnimationController> m_scrollbarAnimationController;
 
     // Group of properties that need to be computed based on the layer tree
     // hierarchy before layers can be drawn.
     DrawProperties<LayerImpl, RenderSurfaceImpl> m_drawProperties;
 
     DISALLOW_COPY_AND_ASSIGN(LayerImpl);
 };
 
-void sortLayers(std::vector<LayerImpl*>::iterator first, std::vector<LayerImpl*>::iterator end, LayerSorter*);
-
 }
 
 #endif  // CC_LAYER_IMPL_H_