[animations] Adds metrics for jank on selected layer animations

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 <stddef.h>
 
 #include <memory>
 
@@ skipping 35 matching lines @@
 // LayerAnimator public --------------------------------------------------------
 
 LayerAnimator::LayerAnimator(base::TimeDelta transition_duration)
     : delegate_(NULL),
       preemption_strategy_(IMMEDIATELY_SET_NEW_TARGET),
       is_transition_duration_locked_(false),
       transition_duration_(transition_duration),
       tween_type_(gfx::Tween::LINEAR),
       is_started_(false),
       disable_timer_for_test_(false),
-      adding_animations_(false) {
+      adding_animations_(false),
+      animation_metrics_reporter_(nullptr) {
   animation_player_ =
       cc::AnimationPlayer::Create(cc::AnimationIdProvider::NextPlayerId());
 }
 
 LayerAnimator::~LayerAnimator() {
   for (size_t i = 0; i < running_animations_.size(); ++i) {
     if (running_animations_[i].is_sequence_alive())
       running_animations_[i].sequence()->OnAnimatorDestroyed();
   }
   ClearAnimationsInternal();
@@ skipping 121 matching lines @@
 void LayerAnimator::RemoveThreadedAnimation(int animation_id) {
   animation_player_->RemoveAnimation(animation_id);
 }
 
 cc::AnimationPlayer* LayerAnimator::GetAnimationPlayerForTesting() const {
   return animation_player_.get();
 }
 
 void LayerAnimator::StartAnimation(LayerAnimationSequence* animation) {
   scoped_refptr<LayerAnimator> retain(this);
+  if (animation_metrics_reporter_)
+    animation->SetAnimationMetricsReporter(animation_metrics_reporter_);
   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:
         ImmediatelyAnimateToNewTarget(animation);
         break;
@@ skipping 723 matching lines @@
     const base::WeakPtr<LayerAnimationSequence>& sequence)
     : sequence_(sequence) {
 }
 
 LayerAnimator::RunningAnimation::RunningAnimation(
     const RunningAnimation& other) = default;
 
 LayerAnimator::RunningAnimation::~RunningAnimation() { }
 
 }  // namespace ui