Deflake RenderWidgetHostViewMacTest.TimerBasedPhaseInfo

This test relies on the ordering of delayed and non-delayed tasks
which is a mistake. Changeing it to quit after all tasks have
run makes it reliable.

TBR=asvitkine@chromium.org

Bug: 863341, 891670
Change-Id: Id8dcbda9359a3adcf9688973457edf146d1d070f
Reviewed-on: https://chromium-review.googlesource.com/c/1365447
Commit-Queue: Alex Clarke <alexclarke@chromium.org>
Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#614335}
1 file changed