This will allow us to show the progress when cloning a new repo when running
commands like gclient sync.

R=agable@chromium.org

Bug: 722686
Change-Id: I268cba343ea4c3c024292c9341d5009aa112b184
Reviewed-on: https://chromium-review.googlesource.com/890524
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
Reviewed-by: Aaron Gable <agable@chromium.org>