cc: nine patch: add occlusion support

cc/layers/nine_patch_layer_impl.h

Index: cc/layers/nine_patch_layer_impl.h
diff --git a/cc/layers/nine_patch_layer_impl.h b/cc/layers/nine_patch_layer_impl.h
index 1fe8e7f2a39eef00adcde12f0c688b94f23185d5..3511c3219138dfe4d88a4e5177c0c7ac85fe1f02 100644
--- a/cc/layers/nine_patch_layer_impl.h
+++ b/cc/layers/nine_patch_layer_impl.h
@@ -34,29 +34,52 @@ class CC_EXPORT NinePatchLayerImpl : public UIResourceLayerImpl {
   // The bitmap stretches out the bounds of the layer.  The following picture
   // illustrates the parameters associated with the dimensions.
   //
-  // Layer space layout              Bitmap space layout
+  // Layer space layout
   //
-  // ------------------------       ~~~~~~~~~~ W ~~~~~~~~~~
-  // |          :           |       :     :                |
-  // |          C           |       :     Y                |
-  // |          :           |       :     :                |
-  // |     ------------     |       :~~X~~------------     |
-  // |     |          |     |       :     |          :     |
-  // |     |          |     |       :     |          :     |
-  // |~~A~~|          |~~B~~|       H     |          Q     |
-  // |     |          |     |       :     |          :     |
-  // |     ------------     |       :     ~~~~~P~~~~~      |
-  // |          :           |       :                      |
-  // |          D           |       :                      |
-  // |          :           |       :                      |
-  // ------------------------       ------------------------
+  // --------------------------------
+  // |         :    :               |
+  // |         J    C               |
+  // |         :    :               |
+  // |      ------------------      |
+  // |      |       :        |      |
+  // |~~~I~~|  ------------  |      |
+  // |      |  |          |  |      |
+  // |      |  |          |  |      |
+  // |~~~A~~|~~|          |~~|~B~~~~|
+  // |      |  |          |  |      |
+  // |      L  ------------  |      |
+  // |      |       :        |      |
+  // |      ---K--------------      |
+  // |              D               |
+  // |              :               |
+  // |              :               |
+  // --------------------------------
+  //
+  // Bitmap space layout
+  //
+  // ~~~~~~~~~~ W ~~~~~~~~~~
+  // :     :                |
+  // :     Y                |
+  // :     :                |
+  // :~~X~~------------     |
+  // :     |          :     |
+  // :     |          :     |
+  // H     |          Q     |
+  // :     |          :     |
+  // :     ~~~~~P~~~~~      |
+  // :                      |
+  // :                      |
+  // :                      |
+  // ------------------------
   //
   // |image_bounds| = (W, H)
   // |image_aperture| = (X, Y, P, Q)
   // |border| = (A, C, A + B, C + D)
+  // |occlusion_rectangle| = (I, J, K, L)
   // |fill_center| indicates whether to draw the center quad or not.
   void SetLayout(const gfx::Rect& image_aperture,
                  const gfx::Rect& border,
+                 const gfx::Rect& layer_occlusion,
                  bool fill_center,
                  bool nearest_neighbor);
 
@@ -72,10 +95,21 @@ class CC_EXPORT NinePatchLayerImpl : public UIResourceLayerImpl {
   NinePatchLayerImpl(LayerTreeImpl* tree_impl, int id);
 
  private:
+  class Patch {
+   public:
+    Patch(const gfx::Rect& image_rect, const gfx::Rect& layer_rect);
+
+    gfx::Rect image_rect;
+    gfx::Rect layer_rect;
+  };
+
   const char* LayerTypeAsString() const override;
 
   void CheckGeometryLimitations();
 
+  std::vector<Patch> ComputeQuadsWithOcclusion() const;
+  std::vector<Patch> ComputeQuadsWithoutOcclusion() const;
+
   // The transparent center region that shows the parent layer's contents in
   // image space.
   gfx::Rect image_aperture_;
@@ -87,6 +121,8 @@ class CC_EXPORT NinePatchLayerImpl : public UIResourceLayerImpl {
 
   bool nearest_neighbor_;
 
+  gfx::Rect layer_occlusion_;
+
   DISALLOW_COPY_AND_ASSIGN(NinePatchLayerImpl);
 };