[animations] Adds metrics for jank on selected layer animations

ui/compositor/layer_animation_sequence.cc

Index: ui/compositor/layer_animation_sequence.cc
diff --git a/ui/compositor/layer_animation_sequence.cc b/ui/compositor/layer_animation_sequence.cc
index 773cbb4021cee7a9728bee6d9eb4c7fb48823739..d1739e7ee06ee096d2714642848e9fc7cc31ae02 100644
--- a/ui/compositor/layer_animation_sequence.cc
+++ b/ui/compositor/layer_animation_sequence.cc
@@ -22,8 +22,8 @@ LayerAnimationSequence::LayerAnimationSequence()
       waiting_for_group_start_(false),
       animation_group_id_(0),
       last_progressed_fraction_(0.0),
-      weak_ptr_factory_(this) {
-}
+      animation_metrics_reporter_(nullptr),
+      weak_ptr_factory_(this) {}
 
 LayerAnimationSequence::LayerAnimationSequence(
     std::unique_ptr<LayerAnimationElement> element)
@@ -33,6 +33,7 @@ LayerAnimationSequence::LayerAnimationSequence(
       waiting_for_group_start_(false),
       animation_group_id_(0),
       last_progressed_fraction_(0.0),
+      animation_metrics_reporter_(nullptr),
       weak_ptr_factory_(this) {
   AddElement(std::move(element));
 }
@@ -186,6 +187,7 @@ void LayerAnimationSequence::Abort(LayerAnimationDelegate* delegate) {
 void LayerAnimationSequence::AddElement(
     std::unique_ptr<LayerAnimationElement> element) {
   properties_ |= element->properties();
+  element->set_animation_metrics_reporter(animation_metrics_reporter_);
   elements_.push_back(std::move(element));
 }
 
@@ -243,6 +245,13 @@ void LayerAnimationSequence::OnAnimatorDestroyed() {
   }
 }
 
+void LayerAnimationSequence::SetAnimationMetricsReporter(
+    AnimationMetricsReporter* reporter) {
+  animation_metrics_reporter_ = reporter;
+  for (auto& element : elements_)
+    element->set_animation_metrics_reporter(animation_metrics_reporter_);
+}
+
 size_t LayerAnimationSequence::size() const {
   return elements_.size();
 }