cc : Use effect tree to determine if a layer is inside replica

cc/trees/layer_tree_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/layer_tree_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 843 matching lines @@
         settings().minimum_occlusion_tracking_size);
 
     // LayerIterator is used here instead of CallFunctionForSubtree to only
     // UpdateTilePriorities on layers that will be visible (and thus have valid
     // draw properties) and not because any ordering is required.
     LayerIterator end = LayerIterator::End(&render_surface_layer_list_);
     for (LayerIterator it = LayerIterator::Begin(&render_surface_layer_list_);
          it != end; ++it) {
       occlusion_tracker.EnterLayer(it);
 
-      // There are very few render targets so this should be cheap to do for
-      // each layer instead of something more complicated.
-      bool inside_replica = false;
-      LayerImpl* layer = it->render_target();
-      while (layer && !inside_replica) {
-        if (layer->render_target()->has_replica())
-          inside_replica = true;
-        layer = layer->render_target()->parent();
-      }
+      bool inside_replica = it->render_target()->InsideReplica();
 
       // Don't use occlusion if a layer will appear in a replica, since the
       // tile raster code does not know how to look for the replica and would
       // consider it occluded even though the replica is visible.
       // Since occlusion is only used for browser compositor (i.e.
       // use_occlusion_for_tile_prioritization) and it won't use replicas,
       // this should matter not.
 
       if (it.represents_itself()) {
         Occlusion occlusion =
@@ skipping 1223 matching lines @@
 }
 
 void LayerTreeImpl::ResetAllChangeTracking(PropertyTrees::ResetFlags flag) {
   layers_that_should_push_properties_.clear();
   for (auto* layer : *this)
     layer->ResetChangeTracking();
   property_trees_.ResetAllChangeTracking(flag);
 }
 
 }  // namespace cc