If the revision has not yet propagated, then we never retry, because the amount of time to fetch HEAD already exceeds the deadline.

Bug: 771007
Change-Id: I91ac30b2b53b4f75729357b3298c52856a4d350e
Reviewed-on: https://chromium-review.googlesource.com/729328
Commit-Queue: Jao-ke Chin-Lee <jchinlee@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>