mix-blend-mode implementation for accelerated layers

cc/layers/render_surface_impl.h

Index: cc/layers/render_surface_impl.h
diff --git a/cc/layers/render_surface_impl.h b/cc/layers/render_surface_impl.h
index f887a659394f2addebc13fc5f1b7b66115dcda3e..2f49776797eefb158e315199592b12a4e2f0a4a2 100644
--- a/cc/layers/render_surface_impl.h
+++ b/cc/layers/render_surface_impl.h
@@ -46,6 +46,11 @@ class CC_EXPORT RenderSurfaceImpl {
   void SetDrawOpacity(float opacity) { draw_opacity_ = opacity; }
   float draw_opacity() const { return draw_opacity_; }
 
+  void SetHasBlendMode(bool has_blend_mode) {
+    has_blend_mode_ = has_blend_mode;
+  }
+  bool has_blend_mode() const { return has_blend_mode_; }
+
   void SetNearestAncestorThatMovesPixels(RenderSurfaceImpl* surface) {
     nearest_ancestor_that_moves_pixels_ = surface;
   }
@@ -149,6 +154,7 @@ class CC_EXPORT RenderSurfaceImpl {
 
   float draw_opacity_;
   bool draw_opacity_is_animating_;
+  bool has_blend_mode_;
   gfx::Transform draw_transform_;
   gfx::Transform screen_space_transform_;
   gfx::Transform replica_draw_transform_;