These methods can mutate the display resources. Necessary for getting
rid of ProxyContext and for the Vulkan error refactor.

Bug: angleproject:2714
Bug: angleproject:2713
Change-Id: Ibffb1a382ecb064daaa7c664f9fc65cbcf927b37
Reviewed-on: https://chromium-review.googlesource.com/1128927Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>