[WIP] Implement BackGroundFilter as seperate layer in cc

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 75a5d6e720e76572268f2a7b5e32570c24647d83..0f7f7a175c2b1cb571e4e7d8a11599d644900613 100644
--- a/cc/output/gl_renderer.h
+++ b/cc/output/gl_renderer.h
@@ -41,6 +41,7 @@ class TextureDrawQuad;
 class TextureMailboxDeleter;
 class GeometryBinding;
 class ScopedEnsureFramebufferAllocation;
+class FilterDrawQuad;
 
 // Class that handles drawing of composited render layers using GL.
 class CC_EXPORT GLRenderer : public DirectRenderer {
@@ -167,6 +168,8 @@ class CC_EXPORT GLRenderer : public DirectRenderer {
                         const YUVVideoDrawQuad* quad);
   void DrawPictureQuad(const DrawingFrame* frame,
                        const PictureDrawQuad* quad);
+  void DrawFilterContentQuad(const DrawingFrame* frame,
+                             const FilterDrawQuad* quad);
 
   void SetShaderOpacity(float opacity, int alpha_location);
   void SetShaderQuadF(const gfx::QuadF& quad, int quad_location);