These flags were written but they were never read.

TEST=compile
BUG=angleproject:1116

Change-Id: I41e3e89f13861ebda4828c76c753ca17c74c4358
Reviewed-on: https://chromium-review.googlesource.com/294931Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Tested-by: Olli Etuaho <oetuaho@nvidia.com>