cc: Apply occlusion before creating quads in RenderSurfaceImpl.

cc/layers/quad_sink.h

Index: cc/layers/quad_sink.h
diff --git a/cc/layers/quad_sink.h b/cc/layers/quad_sink.h
index 1b824703aadbdadb28575b980e46076bbeca70e7..add4e996af5d511cd8a2cd03fc949b9410e8d1b3 100644
--- a/cc/layers/quad_sink.h
+++ b/cc/layers/quad_sink.h
@@ -16,6 +16,7 @@ class Transform;
 namespace cc {
 
 class DrawQuad;
+class LayerImpl;
 class SharedQuadState;
 
 class CC_EXPORT QuadSink {
@@ -32,6 +33,10 @@ class CC_EXPORT QuadSink {
       const gfx::Rect& content_rect,
       const gfx::Transform& draw_transform) = 0;
 
+  virtual gfx::Rect UnoccludedContributingSurfaceContentRect(
+      const gfx::Rect& content_rect,
+      const gfx::Transform& draw_transform) = 0;
+
   // Returns true if the quad is added to the list, and false if the quad is
   // entirely culled.
   virtual bool MaybeAppend(scoped_ptr<DrawQuad> draw_quad) = 0;