Move LayerSorter to exist locally only in layer_tree_host_common

cc/layer_tree_host_common.h

Index: cc/layer_tree_host_common.h
diff --git a/cc/layer_tree_host_common.h b/cc/layer_tree_host_common.h
index 2a812f2b52f0f66c50262817f0c7e407b11955d8..21dc29586105f8b3f1cdbeb97b5bff38ee9a8b66 100644
--- a/cc/layer_tree_host_common.h
+++ b/cc/layer_tree_host_common.h
@@ -15,7 +15,6 @@
 namespace cc {
 
 class LayerImpl;
-class LayerSorter;
 class Layer;
 
 class CC_EXPORT LayerTreeHostCommon {
@@ -23,7 +22,7 @@ public:
     static gfx::Rect calculateVisibleRect(const gfx::Rect& targetSurfaceRect, const gfx::Rect& layerBoundRect, const gfx::Transform&);
 
     static void calculateDrawProperties(Layer* rootLayer, const gfx::Size& deviceViewportSize, float deviceScaleFactor, float pageScaleFactor, int maxTextureSize, std::vector<scoped_refptr<Layer> >& renderSurfaceLayerList);
-    static void calculateDrawProperties(LayerImpl* rootLayer, const gfx::Size& deviceViewportSize, float deviceScaleFactor, float pageScaleFactor, LayerSorter*, int maxTextureSize, std::vector<LayerImpl*>& renderSurfaceLayerList);
+    static void calculateDrawProperties(LayerImpl* rootLayer, const gfx::Size& deviceViewportSize, float deviceScaleFactor, float pageScaleFactor, int maxTextureSize, std::vector<LayerImpl*>& renderSurfaceLayerList);
 
     // Performs hit testing for a given renderSurfaceLayerList.
     static LayerImpl* findLayerThatIsHitByPoint(const gfx::PointF& screenSpacePoint, std::vector<LayerImpl*>& renderSurfaceLayerList);