[WIP] Implement BackGroundFilter as seperate layer in cc

cc/output/gl_renderer.cc

Index: cc/output/gl_renderer.cc
diff --git a/cc/output/gl_renderer.cc b/cc/output/gl_renderer.cc
index 92af7bc34dc09ca578c4ed4067b9c3943ecf8ecf..a78b2633d851207da3ed4d939f2e3811dc8cb87c 100644
--- a/cc/output/gl_renderer.cc
+++ b/cc/output/gl_renderer.cc
@@ -22,6 +22,7 @@
 #include "cc/output/gl_frame_data.h"
 #include "cc/output/output_surface.h"
 #include "cc/output/render_surface_filters.h"
+#include "cc/quads/filter_draw_quad.h"
 #include "cc/quads/picture_draw_quad.h"
 #include "cc/quads/render_pass.h"
 #include "cc/quads/stream_video_draw_quad.h"
@@ -537,6 +538,9 @@ void GLRenderer::DoDrawQuad(DrawingFrame* frame, const DrawQuad* quad) {
     case DrawQuad::DEBUG_BORDER:
       DrawDebugBorderQuad(frame, DebugBorderDrawQuad::MaterialCast(quad));
       break;
+    case DrawQuad::FILTER_CONTENT:
+      DrawFilterContentQuad(frame, FilterDrawQuad::MaterialCast(quad));
+      break;
     case DrawQuad::IO_SURFACE_CONTENT:
       DrawIOSurfaceQuad(frame, IOSurfaceDrawQuad::MaterialCast(quad));
       break;
@@ -3223,4 +3227,8 @@ void GLRenderer::ScheduleOverlays(DrawingFrame* frame) {
   }
 }
 
+void GLRenderer::DrawFilterContentQuad(const DrawingFrame* frame,
+                                       const FilterDrawQuad* quad) {
+}
+
 }  // namespace cc