Add error check on resuming XFB with deleted buffer. Bug: chromium:1305190 Change-Id: I22c6f6400b05ca32c922fba9a3b9d4b5841ca8b8 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3578378 Auto-Submit: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>