[ScrollTimeline] Upstream root scroller currentTime test to WPT

This CL upstreams the root scroller currentTime test to WPT. The quirks
mode test is left in fast/animation/scroll-animations as it is just a
crash test for running in quirks mode, which is Chrome-specific and not
upstreamable.

There are no behavioral changes.

Bug: 911254
Change-Id: Ia8270f11ede8746cbdecf7ba57aeca60eee6fb78
Reviewed-on: https://chromium-review.googlesource.com/c/1366367
Commit-Queue: Stephen McGruer <smcgruer@chromium.org>
Reviewed-by: Majid Valipour <majidvp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615225}
1 file changed