GitLab

Add animation smoothness metrics for fade-in/fade-out animation of tab
hover card. It uses ThroughputTracker to track throughput and calculate
smoothness.

Bug: 1060816
Change-Id: I5e9c15a9a5b4320214c1cc27a1deae9230466ec6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2231583Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Yichen Zhou <yichenz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#776242}