EGL_CONTEXT_OPENGL_RESET_NOTIFICATION_STRATEGY_EXT from
EXT_create_context_robustness must be used with GLES instead.

BUG=angleproject:2213

Change-Id: Icaf3c7550c4eb7cb61c6d4ed37adba7824ca4bc8
Reviewed-on: https://chromium-review.googlesource.com/759122Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>