cbuildbot: make Android PFQ slave builds sync properly

BUG=chromium:589551
TEST=cbuildbot_unittest

Change-Id: Idecaa6ed98ba37b5c8002d50c96692620c903eed
Reviewed-on: https://chromium-review.googlesource.com/329390
Commit-Ready: David Riley <davidriley@chromium.org>
Tested-by: David Riley <davidriley@chromium.org>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
1 file changed