cc : Compute subtree has copy requests before property tree building

cc/trees/layer_tree_host.h

 // 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.
 
 #ifndef CC_TREES_LAYER_TREE_HOST_H_
 #define CC_TREES_LAYER_TREE_HOST_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 323 matching lines @@
   void UnregisterLayer(Layer* layer);
   Layer* LayerById(int id) const;
 
   size_t NumLayers() const;
 
   bool in_update_property_trees() const { return in_update_property_trees_; }
   bool PaintContent(const LayerList& update_layer_list,
                     bool* content_is_suitable_for_gpu);
   bool in_paint_layer_contents() const { return in_paint_layer_contents_; }
 
+  void SetHasCopyRequest(bool has_copy_request);
+  bool has_copy_request() const { return has_copy_request_; }
+
   void AddLayerShouldPushProperties(Layer* layer);
   void RemoveLayerShouldPushProperties(Layer* layer);
   std::unordered_set<Layer*>& LayersThatShouldPushProperties();
   bool LayerNeedsPushPropertiesForTesting(Layer* layer) const;
 
   void SetPageScaleFromImplSide(float page_scale);
   void SetElasticOverscrollFromImplSide(gfx::Vector2dF elastic_overscroll);
   gfx::Vector2dF elastic_overscroll() const { return elastic_overscroll_; }
 
   void UpdateHudLayer(bool show_hud_info);
@@ skipping 250 matching lines @@
   std::unordered_set<Layer*> layers_that_should_push_properties_;
 
   // Layer id to Layer map.
   std::unordered_map<int, Layer*> layer_id_map_;
 
   std::unordered_map<ElementId, Layer*, ElementIdHash> element_layers_map_;
 
   bool in_paint_layer_contents_ = false;
   bool in_update_property_trees_ = false;
 
+  // This is true if atleast one layer in the layer tree has a copy request. We
+  // use this bool to decide whether we need to compute subtree has copy request
+  // for every layer during property tree building.
+  bool has_copy_request_ = false;
+
   MutatorHost* mutator_host_;
 
   std::vector<std::pair<sk_sp<const SkImage>, base::Callback<void(bool)>>>
       queued_image_decodes_;
 
   bool did_navigate_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHost);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_H_