Disable warnings-as-error in GLSLTest. This disables the warnings in the FragData test. We were getting errors in Debug from the multithreading compile implementation. Bug: chromium:931294 Change-Id: I6d1424e54335534f794884e40f527b5464113084 Reviewed-on: https://chromium-review.googlesource.com/c/1465960 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>