GitLab

Make stopSmoothnessTracking to return ThroughputTrackerAnimationData
that contains raw metrics data so that tast side could calculate
jank metrics as well as smoothness.

Bug: 1132017
Change-Id: If1a64d1b681505d0baece3bd7650c1e8a04351b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2488664
Commit-Queue: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Jun Mukai <mukai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#820363}