DisplayGLX: disable the GLES backend on Intel and NVIDIA This is to fix failures in the automated testing while we work on them. BUG=angleproject:1303 Change-Id: I0813b5cf1dca1e329504704c70b9d2b0c34d003b Reviewed-on: https://chromium-review.googlesource.com/324460 Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Corentin Wallez <cwallez@chromium.org> Tested-by: Corentin Wallez <cwallez@chromium.org>