This removes the use of the ErrorOrResult pattern in Renderer11.

Bug: angleproject:2738
Change-Id: Icc046ddd86394df56ca1acd10b1804fd6afa8ad0
Reviewed-on: https://chromium-review.googlesource.com/1142953Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>