Change ui::wm::Shadow to use cc::NinePatchLayer.

ui/compositor/layer.h

Index: ui/compositor/layer.h
diff --git a/ui/compositor/layer.h b/ui/compositor/layer.h
index 03041edb872c1f4f66cec65a457f3ebf5aecd4ba..021d734defd7b6f45366a8c476e763825a70a8fd 100644
--- a/ui/compositor/layer.h
+++ b/ui/compositor/layer.h
@@ -36,6 +36,7 @@ class CopyOutputRequest;
 class DelegatedFrameProvider;
 class DelegatedRendererLayer;
 class Layer;
+class NinePatchLayer;
 class ResourceUpdateQueue;
 class SolidColorLayer;
 class TextureLayer;
@@ -276,6 +277,12 @@ class COMPOSITOR_EXPORT Layer
   // Sets the layer's fill color.  May only be called for LAYER_SOLID_COLOR.
   void SetColor(SkColor color);
 
+  // Updates the nine patch layer's bitmap, aperture and border parameters.
+  // May only be called for LAYER_NINE_PATCH.
+  void UpdateNinePatchLayer(const SkBitmap& bitmap,
+                            const gfx::Rect& aperture,
+                            const gfx::Rect& border);
+
   // Adds |invalid_rect| to the Layer's pending invalid rect and calls
   // ScheduleDraw(). Returns false if the paint request is ignored.
   bool SchedulePaint(const gfx::Rect& invalid_rect);
@@ -469,6 +476,7 @@ class COMPOSITOR_EXPORT Layer
   // Ownership of the layer is held through one of the strongly typed layer
   // pointers, depending on which sort of layer this is.
   scoped_refptr<cc::Layer> content_layer_;
+  scoped_refptr<cc::NinePatchLayer> nine_patch_layer_;
   scoped_refptr<cc::TextureLayer> texture_layer_;
   scoped_refptr<cc::SolidColorLayer> solid_color_layer_;
   scoped_refptr<cc::DelegatedRendererLayer> delegated_renderer_layer_;