tree d6a37022d668f7e562339a364571f1b370fec619
parent 6693cdfab4e7dc0fa7de7a737ecc60beedc02388
author Olga Gerchikov <gerchiko@microsoft.com> 1551459139 -0800
committer Robert Ma <bob1211@gmail.com> 1552065367 -0500

Implemented setPlaybackRate for scroll-linked Worklet Animations.

• Updated logic of calculating initial current time of non-composited scroll-linked animations to
  ensure that the start time is always initialized to zero.
• Changed signature of cc::ScrollTimeline::CurrentTime to return base::Optional<base::TimeTicks>.
  This is to enforce cc: WorkletAnimation::CurrentTime operating in the same units of
  base::TimeTicks and correctly handling NaN values.
• Adjusted start time of scroll-linked animations when playback rate is updated.

Bug: 852475
Change-Id: Iffd966c1b3ef6d821eef7cc2f6f79dae790a69f3
Reviewed-on: https://chromium-review.googlesource.com/c/1461513
Commit-Queue: Olga Gerchikov <gerchiko@microsoft.com>
Reviewed-by: Stephen McGruer <smcgruer@chromium.org>
Reviewed-by: Majid Valipour <majidvp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#636836}