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

BUG=angleproject:1324

Change-Id: Ie7dd70bde1490c8623910c6d319128ca1225990a
Reviewed-on: https://chromium-review.googlesource.com/329156Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>