This provides easy implementation with the Chromium perf bots.

BUG=angleproject:744

Change-Id: I71c04e3d67cae9344ddca9fd95fd3c9849494922
Reviewed-on: https://chromium-review.googlesource.com/260644Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>