cc: nine patch: add occlusion support

ui/compositor/layer.h

 // Copyright (c) 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 UI_COMPOSITOR_LAYER_H_
 #define UI_COMPOSITOR_LAYER_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 303 matching lines @@
   // Sets the layer's fill color.  May only be called for LAYER_SOLID_COLOR.
   void SetColor(SkColor color);
   SkColor GetTargetColor();
   SkColor background_color() const;
 
   // Updates the nine patch layer's image, aperture and border. May only be
   // called for LAYER_NINE_PATCH.
   void UpdateNinePatchLayerImage(const gfx::ImageSkia& image);
   void UpdateNinePatchLayerAperture(const gfx::Rect& aperture_in_dip);
   void UpdateNinePatchLayerBorder(const gfx::Rect& border);
+  // Updates the area completely occluded by another layer, this can be an
+  // empty rectangle if nothing is occluded.
+  void UpdateNinePatchOcclusion(const gfx::Rect& occlusion);
 
   // 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);
 
   // Schedules a redraw of the layer tree at the compositor.
   // Note that this _does not_ invalidate any region of this layer; use
   // SchedulePaint() for that.
   void ScheduleDraw();
 
@@ skipping 195 matching lines @@
   // The texture scale.
   float texture_x_scale_;
   float texture_y_scale_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_LAYER_H_