mix-blend-mode implementation for accelerated layers

cc/output/gl_renderer.h

Index: cc/output/gl_renderer.h
diff --git a/cc/output/gl_renderer.h b/cc/output/gl_renderer.h
index d65e6381723cd1b86a146a5ef6078d95f7fa6d3b..9043980797de93d8465c1579aefd13bf7941b944 100644
--- a/cc/output/gl_renderer.h
+++ b/cc/output/gl_renderer.h
@@ -101,7 +101,8 @@ class CC_EXPORT GLRenderer : public DirectRenderer {
                                  scoped_ptr<CopyOutputRequest> request);
   void GetFramebufferTexture(unsigned texture_id,
                              ResourceFormat texture_format,
-                             gfx::Rect device_rect);
+                             gfx::Rect device_rect,
+                             bool is_texture_storage);
   void ReleaseRenderPassTextures();
 
   void SetStencilEnabled(bool enabled);
@@ -151,11 +152,12 @@ class CC_EXPORT GLRenderer : public DirectRenderer {
                             const CheckerboardDrawQuad* quad);
   void DrawDebugBorderQuad(const DrawingFrame* frame,
                            const DebugBorderDrawQuad* quad);
-  scoped_ptr<ScopedResource> DrawBackgroundFilters(
+  scoped_ptr<ScopedResource> GetBackgroundWithFilters(
       DrawingFrame* frame,
       const RenderPassDrawQuad* quad,
       const gfx::Transform& contents_device_transform,
-      const gfx::Transform& contents_device_transformInverse);
+      const gfx::Transform& contents_device_transformInverse,
+      bool* background_changed);
   void DrawRenderPassQuad(DrawingFrame* frame, const RenderPassDrawQuad* quad);
   void DrawSolidColorQuad(const DrawingFrame* frame,
                           const SolidColorDrawQuad* quad);
@@ -437,6 +439,7 @@ class CC_EXPORT GLRenderer : public DirectRenderer {
   gfx::Rect viewport_;
   bool is_backbuffer_discarded_;
   bool is_using_bind_uniform_;
+  bool is_using_texture_storage_;
   bool visible_;
   bool is_scissor_enabled_;
   bool stencil_shadow_;