mix-blend-mode implementation for accelerated layers

cc/quads/render_pass_draw_quad.h

Index: cc/quads/render_pass_draw_quad.h
diff --git a/cc/quads/render_pass_draw_quad.h b/cc/quads/render_pass_draw_quad.h
index e253dec430b4dfe9683ac983f8e739974fdc9665..65d00456d1ebc341a9467e462bc77db516cd483e 100644
--- a/cc/quads/render_pass_draw_quad.h
+++ b/cc/quads/render_pass_draw_quad.h
@@ -29,7 +29,8 @@ class CC_EXPORT RenderPassDrawQuad : public DrawQuad {
               gfx::RectF mask_uv_rect,
               const FilterOperations& filters,
               skia::RefPtr<SkImageFilter> filter,
-              const FilterOperations& background_filters);
+              const FilterOperations& background_filters,
+              SkXfermode::Mode blend_mode = SkXfermode::kSrcOver_Mode);

[shawnsingh, 2013/09/25 05:33:53]

would it make more sense to put this in the SharedQuadState instead?  It won't
change for each quad within one layer.

[rosca, 2013/09/25 18:00:00]

Done.

 
   void SetAll(const SharedQuadState* shared_quad_state,
               gfx::Rect rect,
@@ -43,7 +44,8 @@ class CC_EXPORT RenderPassDrawQuad : public DrawQuad {
               gfx::RectF mask_uv_rect,
               const FilterOperations& filters,
               skia::RefPtr<SkImageFilter> filter,
-              const FilterOperations& background_filters);
+              const FilterOperations& background_filters,
+              SkXfermode::Mode blend_mode = SkXfermode::kSrcOver_Mode);
 
   scoped_ptr<RenderPassDrawQuad> Copy(
       const SharedQuadState* copied_shared_quad_state,
@@ -65,6 +67,8 @@ class CC_EXPORT RenderPassDrawQuad : public DrawQuad {
   // background of the render pass, from behind it.
   FilterOperations background_filters;
 
+  SkXfermode::Mode blend_mode;
+
   virtual void IterateResources(const ResourceIteratorCallback& callback)
       OVERRIDE;