This helps make dEQP support platform agnostic

BUG=angleproject:892

Change-Id: Ifd9436caa8c79018a053c27e32b514ef9ebee707
Reviewed-on: https://chromium-review.googlesource.com/273596Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Corentin Wallez <cwallez@chromium.org>