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

cc/layers/layer_impl.cc

 // Copyright 2012 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/layers/layer_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1552 matching lines @@
   return MathUtil::MapEnclosingClippedRect(scaled_draw_transform,
                                            gfx::Rect(scaled_bounds));
 }
 
 bool LayerImpl::IsHidden() const {
   EffectTree& effect_tree = layer_tree_impl_->property_trees()->effect_tree;
   EffectNode* node = effect_tree.Node(effect_tree_index_);
   return node->data.screen_space_opacity == 0.f;
 }
 
+bool LayerImpl::InsideReplica() const {
+  // There are very few render targets so this should be cheap to do for each
+  // layer instead of something more complicated.
+  EffectTree& effect_tree = layer_tree_impl_->property_trees()->effect_tree;
+  EffectNode* node = effect_tree.Node(effect_tree_index_);
+  bool inside_replica = false;
+
+  while (node && !inside_replica) {
+    EffectNode* target_node = effect_tree.Node(node->data.target_id);
+    LayerImpl* target_layer =
+        layer_tree_impl()->LayerById(target_node->owner_id);
+    DCHECK(target_layer);
+    if (target_layer->has_replica())
+      inside_replica = true;

[ajuma, 2016/03/29 13:41:10]

We can early-return here.

[jaydasika, 2016/03/29 16:03:45]

Done.

+    node = effect_tree.parent(target_node);
+  }
+
+  return inside_replica;
+}
+
 float LayerImpl::GetIdealContentsScale() const {
   float page_scale = IsAffectedByPageScale()
                          ? layer_tree_impl()->current_page_scale_factor()
                          : 1.f;
   float device_scale = layer_tree_impl()->device_scale_factor();
 
   float default_scale = page_scale * device_scale;
   if (!layer_tree_impl()
            ->settings()
            .layer_transforms_should_scale_layer_contents) {
     return default_scale;
   }
 
   gfx::Vector2dF transform_scales = MathUtil::ComputeTransform2dScaleComponents(
       DrawTransform(), default_scale);
   return std::max(transform_scales.x(), transform_scales.y());
 }
 
 }  // namespace cc