On a loaded machine, Sleep(0) can be very slow (40+ms) while Sleep(1) is
consistantly 1-2ms.

BUG=488571

Change-Id: I71de0b4cfc334a2476b7c613c103e77fe759041d
Reviewed-on: https://chromium-review.googlesource.com/273183Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>