These sample utils can also be useful for writing perf tests.

BUG=angleproject:1164

Change-Id: I44b5d63b57bfce7a541442fd02cd729a1bab17f0
Reviewed-on: https://chromium-review.googlesource.com/301468Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Tryjob-Request: Jamie Madill <jmadill@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>