This test was checking out-of-bounds. The bug only showed up in
Linux.

BUG=angle:741

Change-Id: I4cb45fc00dbb0bf9713f735a20fb6fd04bc95140
Reviewed-on: https://chromium-review.googlesource.com/221057Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>