Reset notification behavior is defined in the
GL_EXT_robustness extension, and the resulting
context must support the extension and the
specified reset strategy. So if the ext is not
supported, it should disable delivery of reset
notifications.

Bug: angleproject:4823
Change-Id: I49b9364a83eab9ebc0fdca3b1dc075c1a43070cf
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2302874
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>