CC Animation: Make LayerAnimationController to have just one value observer.

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"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "cc/animation/animation_curve.h"
 #include "cc/animation/animation_delegate.h"
 #include "cc/animation/layer_animation_controller.h"
+#include "cc/animation/layer_animation_value_observer.h"
 #include "cc/animation/layer_animation_value_provider.h"
 #include "cc/base/cc_export.h"
 
 namespace gfx {
 class ScrollOffset;
 class Transform;
 }
 
 namespace cc {
 
 class AnimationHost;
 class AnimationPlayer;
 class FilterOperations;
 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,
+                                    public LayerAnimationValueObserver,
                                     public LayerAnimationValueProvider {
  public:
   static std::unique_ptr<ElementAnimations> Create(AnimationHost* host);
   ~ElementAnimations() override;
 
   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);
   void DestroyLayerAnimationController();
 
   void LayerRegistered(int layer_id, LayerTreeType tree_type);
   void LayerUnregistered(int layer_id, LayerTreeType tree_type);
 
-  bool has_active_value_observer_for_testing() const {
-    return !!active_value_observer_;
+  bool needs_active_value_observations() const {
+    return layer_animation_controller_->needs_active_value_observations();
   }
-  bool has_pending_value_observer_for_testing() const {
-    return !!pending_value_observer_;
+  bool needs_pending_value_observations() const {
+    return layer_animation_controller_->needs_pending_value_observations();
   }
 
   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(); }
 
@@ skipping 15 matching lines @@
 
   void AddEventObserver(LayerAnimationEventObserver* observer);
   void RemoveEventObserver(LayerAnimationEventObserver* observer);
 
  private:
   // TODO(loyso): Erase this when LAC merged into ElementAnimations.
   friend class AnimationHost;
 
   explicit ElementAnimations(AnimationHost* host);
 
-  void SetFilterMutated(LayerTreeType tree_type,
-                        const FilterOperations& filters);
-  void SetOpacityMutated(LayerTreeType tree_type, float opacity);
-  void SetTransformMutated(LayerTreeType tree_type,
-                           const gfx::Transform& transform);
-  void SetScrollOffsetMutated(LayerTreeType tree_type,
-                              const gfx::ScrollOffset& scroll_offset);
-  void SetTransformIsPotentiallyAnimatingChanged(LayerTreeType tree_type,
-                                                 bool is_animating);
+  // 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;
+  void OnTransformIsPotentiallyAnimatingChanged(LayerTreeType tree_type,
+                                                bool is_animating) override;
 
   void CreateActiveValueObserver();
   void DestroyActiveValueObserver();
 
   void CreatePendingValueObserver();
   void DestroyPendingValueObserver();
 
   // AnimationDelegate implementation
   void NotifyAnimationStarted(base::TimeTicks monotonic_time,
                               TargetProperty::Type target_property,
                               int group) override;
   void NotifyAnimationFinished(base::TimeTicks monotonic_time,
                                TargetProperty::Type target_property,
                                int group) override;
   void NotifyAnimationAborted(base::TimeTicks monotonic_time,
                               TargetProperty::Type target_property,
                               int group) override;
   void NotifyAnimationTakeover(base::TimeTicks monotonic_time,
                                TargetProperty::Type target_property,
                                double animation_start_time,
                                std::unique_ptr<AnimationCurve> curve) override;
 
   // LayerAnimationValueProvider implementation.
   gfx::ScrollOffset ScrollOffsetForAnimation() const override;
 
   std::unique_ptr<PlayersList> players_list_;
 
-  class ValueObserver;
-  std::unique_ptr<ValueObserver> active_value_observer_;
-  std::unique_ptr<ValueObserver> pending_value_observer_;
-
   // 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_