CC Animation: Make ElementAnimations a ref-counted object.

cc/animation/element_animations.h

 // Copyright 2015 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_ANIMATION_ELEMENT_ANIMATIONS_H_
 #define CC_ANIMATION_ELEMENT_ANIMATIONS_H_
 
 #include <memory>
 
 #include "base/containers/linked_list.h"
@@ skipping 19 matching lines @@
 class LayerAnimationController;
 enum class LayerTreeType;
 
 // An ElementAnimations owns a list of all AnimationPlayers, attached to
 // the layer. Also, it owns LayerAnimationController instance (1:1
 // relationship)
 // ElementAnimations object redirects all events from LAC to the list
 // of animation layers.
 // This is a CC counterpart for blink::ElementAnimations (in 1:1 relationship).
 // No pointer to/from respective blink::ElementAnimations object for now.
-class CC_EXPORT ElementAnimations : public AnimationDelegate,
+class CC_EXPORT ElementAnimations : public base::RefCounted<ElementAnimations>,
+                                    public AnimationDelegate,
                                     public LayerAnimationValueObserver,
                                     public LayerAnimationValueProvider {
  public:
-  static std::unique_ptr<ElementAnimations> Create(AnimationHost* host);
-  ~ElementAnimations() override;
+  static scoped_refptr<ElementAnimations> Create(AnimationHost* host);
 
   int layer_id() const {
     return layer_animation_controller_ ? layer_animation_controller_->id() : 0;
   }
 
   // Parent AnimationHost.
   AnimationHost* animation_host() { return animation_host_; }
   const AnimationHost* animation_host() const { return animation_host_; }
 
   void CreateLayerAnimationController(int layer_id);
@@ skipping 10 matching lines @@
   }
 
   void AddPlayer(AnimationPlayer* player);
   void RemovePlayer(AnimationPlayer* player);
   bool IsEmpty() const;
 
   typedef base::LinkedList<AnimationPlayer> PlayersList;
   typedef base::LinkNode<AnimationPlayer> PlayersListNode;
   const PlayersList& players_list() const { return *players_list_.get(); }
 
-  void PushPropertiesTo(ElementAnimations* element_animations_impl);
+  void PushPropertiesTo(
+      scoped_refptr<ElementAnimations> element_animations_impl);
 
   void AddAnimation(std::unique_ptr<Animation> animation);
   void PauseAnimation(int animation_id, base::TimeDelta time_offset);
   void RemoveAnimation(int animation_id);
   void AbortAnimation(int animation_id);
   void AbortAnimations(TargetProperty::Type target_property,
                        bool needs_completion = false);
 
   // Returns the active animation animating the given property that is either
   // running, or is next to run, if such an animation exists.
   Animation* GetAnimation(TargetProperty::Type target_property) const;
 
   // Returns the active animation for the given unique animation id.
   Animation* GetAnimationById(int animation_id) const;
 
   void AddEventObserver(LayerAnimationEventObserver* observer);
   void RemoveEventObserver(LayerAnimationEventObserver* observer);
 
  private:
+  friend class base::RefCounted<ElementAnimations>;
+
   // TODO(loyso): Erase this when LAC merged into ElementAnimations.
   friend class AnimationHost;
 
   explicit ElementAnimations(AnimationHost* host);
+  ~ElementAnimations() override;
 
   // LayerAnimationValueObserver implementation.
   void OnFilterAnimated(LayerTreeType tree_type,
                         const FilterOperations& filters) override;
   void OnOpacityAnimated(LayerTreeType tree_type, float opacity) override;
   void OnTransformAnimated(LayerTreeType tree_type,
                            const gfx::Transform& transform) override;
   void OnScrollOffsetAnimated(LayerTreeType tree_type,
                               const gfx::ScrollOffset& scroll_offset) override;
   void OnAnimationWaitingForDeletion() override;
@@ skipping 29 matching lines @@
   // LAC is owned by ElementAnimations (1:1 relationship).
   scoped_refptr<LayerAnimationController> layer_animation_controller_;
   AnimationHost* animation_host_;
 
   DISALLOW_COPY_AND_ASSIGN(ElementAnimations);
 };
 
 }  // namespace cc
 
 #endif  // CC_ANIMATION_ELEMENT_ANIMATIONS_H_