gclient syncs unmanaged dependencies when '--revision' files are passed,
regardless of whether the dependency appears in the revision flags or not.

Bug: 853032
Change-Id: I66de0865e1103d92524f565f4392dae24a5648e1
Reviewed-on: https://chromium-review.googlesource.com/1105416Reviewed-by: Aaron Gable <agable@chromium.org>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>