In a Chromium build, this target is built as part of gpu, with the
chromium_code warning settings applied.  Make sure it builds in that
config.

BUG=567877

Change-Id: I7464538a259295d83d990853b06b9ba76b82889d
Reviewed-on: https://chromium-review.googlesource.com/317360Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Nico Weber <thakis@chromium.org>