Chromium seems to destroy the parent window before calling asking to
destroy the EGL surface. We don't want to generate a BadWindow X11
error in this case so we ignore errors when calling XDestroyWindow.

BUG=angleproject:1281

Change-Id: Ie63d188b6206c0ff3b5ac6a5a874e7d6018489e4
Reviewed-on: https://chromium-review.googlesource.com/322361
Tryjob-Request: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Corentin Wallez <cwallez@chromium.org>