GL-CTS: Add option to run on D3D11 refrast. Bug: None Change-Id: Ia28afed48b3fddcd9725094f4892a1aa27957fd4 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3027540 Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>