Fix angle_unittests failures.

BUG=angle:815
TEST=angle_unittests

Change-Id: I4d59f227b7c72f4f456d0a60d8507d097ef05dec
Reviewed-on: https://chromium-review.googlesource.com/226463
Tested-by: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>