Timing out periodically. See the bug for examples.

Bug: angleproject:5994
Change-Id: I717e6c66746a611bb7996c838fa0575b5210aae4
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2909759Reviewed-by: Cody Northrop <cnorthrop@google.com>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Cody Northrop <cnorthrop@google.com>