cc: Move background filters to the effect tree

cc/trees/occlusion_tracker.cc

Index: cc/trees/occlusion_tracker.cc
diff --git a/cc/trees/occlusion_tracker.cc b/cc/trees/occlusion_tracker.cc
index 2cc2b168a05d11aadf6b2e3ecc74be9d2c770c97..fe5b0a355e7d0e6ebb0e7535d4a4450b7b9a6ea7 100644
--- a/cc/trees/occlusion_tracker.cc
+++ b/cc/trees/occlusion_tracker.cc
@@ -191,25 +191,23 @@ void OcclusionTracker::FinishedRenderTarget(const LayerImpl* finished_target) {
 }
 
 static void ReduceOcclusionBelowSurface(
-    const LayerImpl* contributing_layer,
+    const RenderSurfaceImpl* contributing_surface,
     const gfx::Rect& surface_rect,
     const gfx::Transform& surface_transform,
-    const LayerImpl* render_target,
     SimpleEnclosedRegion* occlusion_from_inside_target) {
   if (surface_rect.IsEmpty())
     return;
 
   gfx::Rect affected_area_in_target =
       MathUtil::MapEnclosingClippedRect(surface_transform, surface_rect);
-  if (contributing_layer->render_surface()->is_clipped()) {
-    affected_area_in_target.Intersect(
-        contributing_layer->render_surface()->clip_rect());
+  if (contributing_surface->is_clipped()) {
+    affected_area_in_target.Intersect(contributing_surface->clip_rect());
   }
   if (affected_area_in_target.IsEmpty())
     return;
 
   int outset_top, outset_right, outset_bottom, outset_left;
-  contributing_layer->background_filters().GetOutsets(
+  contributing_surface->BackgroundFilters().GetOutsets(
       &outset_top, &outset_right, &outset_bottom, &outset_left);
 
   // The filter can move pixels from outside of the clip, so allow affected_area
@@ -257,8 +255,6 @@ void OcclusionTracker::LeaveToRenderTarget(const LayerImpl* new_target) {
   // merged out as well but needs to be transformed to the new target.
 
   const RenderSurfaceImpl* old_surface = stack_[last_index].target;
-  const LayerImpl* old_target =
-      new_target->layer_tree_impl()->LayerById(old_surface->OwningLayerId());
 
   SimpleEnclosedRegion old_occlusion_from_inside_target_in_new_target =
       TransformSurfaceOpaqueRegion(
@@ -280,7 +276,7 @@ void OcclusionTracker::LeaveToRenderTarget(const LayerImpl* new_target) {
 
   gfx::Rect unoccluded_surface_rect;
   gfx::Rect unoccluded_replica_rect;
-  if (old_target->background_filters().HasFilterThatMovesPixels()) {
+  if (old_surface->BackgroundFilters().HasFilterThatMovesPixels()) {
     Occlusion surface_occlusion = GetCurrentOcclusionForContributingSurface(
         old_surface->draw_transform());
     unoccluded_surface_rect =
@@ -317,31 +313,23 @@ void OcclusionTracker::LeaveToRenderTarget(const LayerImpl* new_target) {
     }
   }
 
-  if (!old_target->background_filters().HasFilterThatMovesPixels())
+  if (!old_surface->BackgroundFilters().HasFilterThatMovesPixels())
     return;
 
-  ReduceOcclusionBelowSurface(old_target,
-                              unoccluded_surface_rect,
+  ReduceOcclusionBelowSurface(old_surface, unoccluded_surface_rect,
                               old_surface->draw_transform(),
-                              new_target,
                               &stack_.back().occlusion_from_inside_target);
-  ReduceOcclusionBelowSurface(old_target,
-                              unoccluded_surface_rect,
+  ReduceOcclusionBelowSurface(old_surface, unoccluded_surface_rect,
                               old_surface->draw_transform(),
-                              new_target,
                               &stack_.back().occlusion_from_outside_target);
 
   if (!old_surface->HasReplica())
     return;
-  ReduceOcclusionBelowSurface(old_target,
-                              unoccluded_replica_rect,
+  ReduceOcclusionBelowSurface(old_surface, unoccluded_replica_rect,
                               old_surface->replica_draw_transform(),
-                              new_target,
                               &stack_.back().occlusion_from_inside_target);
-  ReduceOcclusionBelowSurface(old_target,
-                              unoccluded_replica_rect,
+  ReduceOcclusionBelowSurface(old_surface, unoccluded_replica_rect,
                               old_surface->replica_draw_transform(),
-                              new_target,
                               &stack_.back().occlusion_from_outside_target);
 }