Implement GL_ARB_create_context_robustness on GLX and WGL BUG=angleproject:1463 Change-Id: I5bdcfd757d6f7d6411558c368fa7a26c8a38c9ba Reviewed-on: https://chromium-review.googlesource.com/365971 Commit-Queue: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>