This will allow us to show more extended error info in about:gpu
in Chromium.

BUG=angleproject:966
BUG=515229

Change-Id: I24c8f33ac3576395ff13dbf7f4664c649af18e33
Reviewed-on: https://chromium-review.googlesource.com/289590Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>