These tests seem to be flaky, and now they are showing up in
a bunch of CLs as failures.

BUG=angleproject:1324

Change-Id: I47c0e0895f8d87fba52084cf571fb453e5d996e0
Reviewed-on: https://chromium-review.googlesource.com/329279Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>