[WIP] Implement BackGroundFilter as seperate layer in cc

cc/output/software_renderer.cc

Index: cc/output/software_renderer.cc
diff --git a/cc/output/software_renderer.cc b/cc/output/software_renderer.cc
index aaa951c2ae35f48047112c20fc0d19f5235ad16a..2be9b91d347197b84ac8c337f12a277f83fe3120 100644
--- a/cc/output/software_renderer.cc
+++ b/cc/output/software_renderer.cc
@@ -15,6 +15,7 @@
 #include "cc/output/software_output_device.h"
 #include "cc/quads/checkerboard_draw_quad.h"
 #include "cc/quads/debug_border_draw_quad.h"
+#include "cc/quads/filter_draw_quad.h"
 #include "cc/quads/picture_draw_quad.h"
 #include "cc/quads/render_pass_draw_quad.h"
 #include "cc/quads/solid_color_draw_quad.h"
@@ -307,6 +308,8 @@ void SoftwareRenderer::DoDrawQuad(DrawingFrame* frame, const DrawQuad* quad) {
     case DrawQuad::DEBUG_BORDER:
       DrawDebugBorderQuad(frame, DebugBorderDrawQuad::MaterialCast(quad));
       break;
+    case DrawQuad::FILTER_CONTENT:
+      DrawFilterQuad(frame, FilterDrawQuad::MaterialCast(quad));
     case DrawQuad::PICTURE_CONTENT:
       DrawPictureQuad(frame, PictureDrawQuad::MaterialCast(quad));
       break;
@@ -409,6 +412,10 @@ void SoftwareRenderer::DrawSolidColorQuad(const DrawingFrame* frame,
   current_canvas_->drawRect(gfx::RectFToSkRect(visible_quad_vertex_rect),
                             current_paint_);
 }
+void SoftwareRenderer::DrawFilterQuad(const DrawingFrame* frame,
+                                      const FilterDrawQuad* quad) {
+  NOTIMPLEMENTED();
+}
 
 void SoftwareRenderer::DrawTextureQuad(const DrawingFrame* frame,
                                        const TextureDrawQuad* quad) {