This is a simpler way of flipping when the client is aware of the extension.
This allows Chrome to render with the correct orientation.

BUG=angleproject:2709

Change-Id: I52216b765a42930f2be043a07fe441a9f875a14d
Reviewed-on: https://chromium-review.googlesource.com/1127342Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Luc Ferron <lucferron@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>