Remove Timer usages from TimerTest

This is part of efforts to replace default timer task runners with
other appropriate task runners in the renderer.

Bug: 624694, 804694
Change-Id: I4115f9c706c735c73bdb14f7243c0e8142293028
Reviewed-on: https://chromium-review.googlesource.com/924101
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Hajime Hoshi <hajimehoshi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537722}
1 file changed