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

ui/compositor/layer_animator.cc

 // 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.
 
 #include "ui/compositor/layer_animator.h"
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/trace_event/trace_event.h"
 #include "cc/animation/animation_id_provider.h"
@@ skipping 97 matching lines @@
 base::TimeDelta LayerAnimator::GetTransitionDuration() const {
   return transition_duration_;
 }
 
 void LayerAnimator::SetDelegate(LayerAnimationDelegate* delegate) {
   if (delegate_ && is_started_) {
     LayerAnimatorCollection* collection = GetLayerAnimatorCollection();
     if (collection)
       collection->StopAnimator(this);
   }
+  SwitchToLayer(delegate ? delegate->GetCcLayer() : nullptr);
   delegate_ = delegate;
   if (delegate_ && is_started_) {
     LayerAnimatorCollection* collection = GetLayerAnimatorCollection();
     if (collection)
       collection->StartAnimator(this);
   }
 }
 
+void LayerAnimator::SwitchToLayer(scoped_refptr<cc::Layer> new_layer) {
+  if (delegate_) {
+    DCHECK(delegate_->GetCcLayer());
+    delegate_->GetCcLayer()->RemoveLayerAnimationEventObserver(this);
+  }
+  if (new_layer)
+    new_layer->AddLayerAnimationEventObserver(this);
+}
+
 void LayerAnimator::StartAnimation(LayerAnimationSequence* animation) {
   scoped_refptr<LayerAnimator> retain(this);
   OnScheduled(animation);
   if (!StartSequenceImmediately(animation)) {
     // Attempt to preempt a running animation.
     switch (preemption_strategy_) {
       case IMMEDIATELY_SET_NEW_TARGET:
         ImmediatelySetNewTarget(animation);
         break;
       case IMMEDIATELY_ANIMATE_TO_NEW_TARGET:
@@ skipping 707 matching lines @@
       running_animations_.erase(running_animations_.begin() + i);
     else
       i++;
   }
 }
 
 LayerAnimatorCollection* LayerAnimator::GetLayerAnimatorCollection() {
   return delegate_ ? delegate_->GetLayerAnimatorCollection() : NULL;
 }
 
+void LayerAnimator::OnAnimationStarted(const cc::AnimationEvent& event) {
+  OnThreadedAnimationStarted(event);
+}
+
 LayerAnimator::RunningAnimation::RunningAnimation(
     const base::WeakPtr<LayerAnimationSequence>& sequence)
     : sequence_(sequence) {
 }
 
 LayerAnimator::RunningAnimation::~RunningAnimation() { }
 
 }  // namespace ui