GitLab

Fix AnimationThroughputReporter leaks its AnimationTracker when
the underlying layer is released before the reporter. In such
case, AnimationTracker holds a ref count of LayerAnimator so
that that the animator and the animation sequences are kept
around even if the underlying layer is released. And the animations
will never run in such case and the tracker is leaked. The CL
fixes the issue by observing LayerDestroyed to clean up.

Also rename IsTrackingAnimation -> HasAnimationsToTrack to better
reflect its meaning that returning a true means there will be
animations to be tracked but does not mean it is tracking them
right now.

Bug: 1158510
Change-Id: I98980522a9b6866b0f635a512d0fbb6987eb2c59
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2590646
Commit-Queue: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: kylechar <kylechar@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#837388}