Transfer LayerImpl ownership to LayerTreeImpl

cc/trees/layer_tree_impl.h

 // 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.
 
 #ifndef CC_TREES_LAYER_TREE_IMPL_H_
 #define CC_TREES_LAYER_TREE_IMPL_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 112 matching lines @@
   void SetNeedsRedraw();
 
   // Tracing methods.
   // ---------------------------------------------------------------------------
   void GetAllPrioritizedTilesForTracing(
       std::vector<PrioritizedTile>* prioritized_tiles) const;
   void AsValueInto(base::trace_event::TracedValue* dict) const;
 
   // Other public methods
   // ---------------------------------------------------------------------------
-  LayerImpl* root_layer() const { return root_layer_.get(); }
+  LayerImpl* root_layer() const { return root_layer_; }
   void SetRootLayer(scoped_ptr<LayerImpl>);
-  scoped_ptr<LayerImpl> DetachLayerTree();
+  scoped_ptr<OwnedLayerImplList> DetachLayers();
+  void ClearLayers();
 
   void SetPropertyTrees(const PropertyTrees property_trees) {
     property_trees_ = property_trees;
     property_trees_.is_main_thread = false;
     property_trees_.is_active = IsActiveTree();
     property_trees_.transform_tree.set_source_to_parent_updates_allowed(false);
   }
   PropertyTrees* property_trees() { return &property_trees_; }
 
   void UpdatePropertyTreesForBoundsDelta();
@@ skipping 154 matching lines @@
 
   void AddLayerShouldPushProperties(LayerImpl* layer);
   void RemoveLayerShouldPushProperties(LayerImpl* layer);
   std::unordered_set<LayerImpl*>& LayersThatShouldPushProperties();
   bool LayerNeedsPushPropertiesForTesting(LayerImpl* layer);
 
   // These should be called by LayerImpl's ctor/dtor.
   void RegisterLayer(LayerImpl* layer);
   void UnregisterLayer(LayerImpl* layer);
 
+  // These manage ownership of the LayerImpl.
+  void AddLayer(scoped_ptr<LayerImpl> layer);
+  scoped_ptr<LayerImpl> RemoveLayer(int id);
+
   size_t NumLayers();
 
   void DidBecomeActive();
 
   // Set on the active tree when the viewport size recently changed
   // and the active tree's size is now out of date.
   bool ViewportSizeInvalid() const;
   void SetViewportSizeInvalid();
   void ResetViewportSizeInvalid();
 
@@ skipping 169 matching lines @@
                                     float max_page_scale_factor);
   bool SetPageScaleFactorLimits(float min_page_scale_factor,
                                 float max_page_scale_factor);
   bool IsViewportLayerId(int id) const;
   void UpdateScrollbars(int scroll_layer_id, int clip_layer_id);
   void DidUpdatePageScale();
   void PushTopControls(const float* top_controls_shown_ratio);
   LayerTreeHostImpl* layer_tree_host_impl_;
   int source_frame_number_;
   int is_first_frame_after_commit_tracker_;
-  scoped_ptr<LayerImpl> root_layer_;
+  LayerImpl* root_layer_;
   HeadsUpDisplayLayerImpl* hud_layer_;
   PropertyTrees property_trees_;
   SkColor background_color_;
   bool has_transparent_background_;
 
   int last_scrolled_layer_id_;
   int overscroll_elasticity_layer_id_;
   int page_scale_layer_id_;
   int inner_viewport_scroll_layer_id_;
   int outer_viewport_scroll_layer_id_;
 
   LayerSelection selection_;
 
   scoped_refptr<SyncedProperty<ScaleGroup>> page_scale_factor_;
   float min_page_scale_factor_;
   float max_page_scale_factor_;
 
   float device_scale_factor_;
   float painted_device_scale_factor_;
 
   scoped_refptr<SyncedElasticOverscroll> elastic_overscroll_;
 
-  using LayerIdMap = std::unordered_map<int, LayerImpl*>;
-  LayerIdMap layer_id_map_;
+  scoped_ptr<OwnedLayerImplList> layers_;
+  LayerImplMap layer_id_map_;
   // Set of layers that need to push properties.
   std::unordered_set<LayerImpl*> layers_that_should_push_properties_;
 
   std::unordered_map<uint64_t, ElementLayers> element_layers_map_;
 
   // Maps from clip layer ids to scroll layer ids.  Note that this only includes
   // the subset of clip layers that act as scrolling containers.  (This is
   // derived from LayerImpl::scroll_clip_layer_ and exists to avoid O(n) walks.)
   std::unordered_map<int, int> clip_scroll_map_;
 
@@ skipping 46 matching lines @@
 
   scoped_ptr<PendingPageScaleAnimation> pending_page_scale_animation_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(LayerTreeImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_IMPL_H_