CC Animations: Make ui::LayerAnimator a LayerAnimationEventObserver (instead of ui::Layer)

ui/compositor/layer_animator.h

 // Copyright (c) 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 UI_COMPOSITOR_LAYER_ANIMATOR_H_
 #define UI_COMPOSITOR_LAYER_ANIMATOR_H_
 
 #include <deque>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "base/time/time.h"
+#include "cc/animation/layer_animation_event_observer.h"
 #include "ui/compositor/compositor_export.h"
 #include "ui/compositor/layer_animation_element.h"
 #include "ui/gfx/animation/tween.h"
 
+namespace cc {
+class Layer;
+}
+
 namespace gfx {
 class Animation;
 class Rect;
 class Transform;
 }
 
 namespace ui {
 class Layer;
 class LayerAnimationSequence;
 class LayerAnimationDelegate;
 class LayerAnimationObserver;
 class LayerAnimatorCollection;
 class ScopedLayerAnimationSettings;
 
 // When a property of layer needs to be changed it is set by way of
 // LayerAnimator. This enables LayerAnimator to animate property changes.
 // NB: during many tests, set_disable_animations_for_test is used and causes
 // all animations to complete immediately. The layer animation is ref counted
 // so that if its owning layer is deleted (and the owning layer is only other
 // class that should ever hold a ref ptr to a LayerAnimator), the animator can
 // ensure that it is not disposed of until it finishes executing. It does this
 // by holding a reference to itself for the duration of methods for which it
 // must guarantee that |this| is valid.
-class COMPOSITOR_EXPORT LayerAnimator : public base::RefCounted<LayerAnimator> {
+class COMPOSITOR_EXPORT LayerAnimator
+    : public base::RefCounted<LayerAnimator>,
+      NON_EXPORTED_BASE(public cc::LayerAnimationEventObserver) {
  public:
   enum PreemptionStrategy {
     IMMEDIATELY_SET_NEW_TARGET,
     IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
     ENQUEUE_NEW_ANIMATION,
     REPLACE_QUEUED_ANIMATIONS,
     BLEND_WITH_CURRENT_ANIMATION
   };
 
   explicit LayerAnimator(base::TimeDelta transition_duration);
@@ skipping 35 matching lines @@
   // Returns the default length of animations, including adjustment for slow
   // animation mode if set.
   base::TimeDelta GetTransitionDuration() const;
 
   // Sets the layer animation delegate the animator is associated with. The
   // animator does not own the delegate. The layer animator expects a non-NULL
   // delegate for most of its operations, so do not call any methods without
   // a valid delegate installed.
   void SetDelegate(LayerAnimationDelegate* delegate);
 
+  // Unsubscribe from |cc_layer_| and subscribe to |new_layer|.
+  void SwitchToLayer(scoped_refptr<cc::Layer> new_layer);
+
   // Sets the animation preemption strategy. This determines the behaviour if
   // a property is set during an animation. The default is
   // IMMEDIATELY_SET_NEW_TARGET (see ImmediatelySetNewTarget below).
   void set_preemption_strategy(PreemptionStrategy strategy) {
     preemption_strategy_ = strategy;
   }
 
   PreemptionStrategy preemption_strategy() const {
     return preemption_strategy_;
   }
@@ skipping 76 matching lines @@
     last_step_time_ = time;
   }
   base::TimeTicks last_step_time() const { return last_step_time_; }
 
   void Step(base::TimeTicks time_now);
 
   void AddToCollection(LayerAnimatorCollection* collection);
   void RemoveFromCollection(LayerAnimatorCollection* collection);
 
  protected:
-  virtual ~LayerAnimator();
+  ~LayerAnimator() override;
 
   LayerAnimationDelegate* delegate() { return delegate_; }
   const LayerAnimationDelegate* delegate() const { return delegate_; }
 
   // Virtual for testing.
   virtual void ProgressAnimation(LayerAnimationSequence* sequence,
                                  base::TimeTicks now);
 
   void ProgressAnimationToEnd(LayerAnimationSequence* sequence);
 
@@ skipping 97 matching lines @@
 
   // Clears the animation queues and notifies any running animations that they
   // have been aborted.
   void ClearAnimationsInternal();
 
   // Cleans up any running animations that may have been deleted.
   void PurgeDeletedAnimations();
 
   LayerAnimatorCollection* GetLayerAnimatorCollection();
 
+  // LayerAnimationEventObserver
+  void OnAnimationStarted(const cc::AnimationEvent& event) override;
+
   // This is the queue of animations to run.
   AnimationQueue animation_queue_;
 
   // The target of all layer animations.
   LayerAnimationDelegate* delegate_;
 
   // The currently running animations.
   RunningAnimations running_animations_;
 
   // Determines how animations are replaced.
@@ skipping 26 matching lines @@
   // Observers are notified when layer animations end, are scheduled or are
   // aborted.
   base::ObserverList<LayerAnimationObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerAnimator);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_LAYER_ANIMATOR_H_