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..4486fc6858a87a2a004739ac9ef7d328692a6c9c 100644
--- a/cc/output/gl_renderer.h
+++ b/cc/output/gl_renderer.h
@@ -151,11 +151,12 @@ 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 +438,7 @@ 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_;