Fix fling scroll flakiness on Vega

Increases the amount of time between polling for scroll quiescence to
500 ms to ensure that the scroll actually started and actually finished
(as opposed to being temporarily frozen due to scroll jank). Scrolling
was taking longer to start on Vega than on smartphones, which was
flakily causing the wait for scroll quiescence to finish before the
scroll actually started.

Bug: 876946
Change-Id: I5d77be8c224bedc7ed6e0d96204307c93366cb0f
Reviewed-on: https://chromium-review.googlesource.com/c/1456209
Reviewed-by: Bill Orr <billorr@chromium.org>
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#630032}
1 file changed