Discovered some of these while investigating Texture dirty bits.

BUG=angleproject:1387

Change-Id: I8b170462bfd283e4b0f9d47b7f7ddbaa7957914d
Reviewed-on: https://chromium-review.googlesource.com/648051Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>