cc : Use effect id to decide if surface contents scale should be applied

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 987 matching lines @@
             occlusion_tracker.OcclusionSurfaceForContributingSurface();
         gfx::Transform draw_transform;
         if (occlusion_surface) {
           // We are calculating transform between two render surfaces. So, we
           // need to apply the surface contents scale at target and remove the
           // surface contents scale at source.
           property_trees()->ComputeTransformToTarget(
               it->render_surface()->TransformTreeIndex(),
               occlusion_surface->EffectTreeIndex(), &draw_transform);
           // We don't have to apply surface contents scale when target is root.
-          if (occlusion_surface->TransformTreeIndex() != 0) {
+          if (occlusion_surface->EffectTreeIndex() != 1) {
             const EffectNode* occlusion_effect_node =
                 property_trees()->effect_tree.Node(
                     occlusion_surface->EffectTreeIndex());
             draw_property_utils::PostConcatSurfaceContentsScale(
                 occlusion_effect_node, &draw_transform);
           }
           const EffectNode* effect_node = property_trees()->effect_tree.Node(
               it->render_surface()->EffectTreeIndex());
           draw_property_utils::ConcatInverseSurfaceContentsScale(
               effect_node, &draw_transform);
@@ skipping 1013 matching lines @@
 
 void LayerTreeImpl::ResetAllChangeTracking() {
   layers_that_should_push_properties_.clear();
   // Iterate over all layers, including masks and replicas.
   for (auto& layer : *layers_)
     layer->ResetChangeTracking();
   property_trees_.ResetAllChangeTracking();
 }
 
 }  // namespace cc