Initially testing will only be on desktop.

Bug: angleproject:5114
Change-Id: I384e4f81cee3a810fad42e73711862725e786ef2
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2854276Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>