The new version v1.12.25 of repo add a new flas "--force-sync"
This will add the bash completion of the flag

Change-Id: I96700a1f13e6c5e1c361c48a4b778b4e7bc5dfed

Checking if main.py exists is better than checking if it
is a file, since it might be a symlink.

Change-Id: I1a9e617470a05c2161479cd3f0a10712a2b9d2c2

From https://raw.github.com/aartamonau/repo.bash_completion/master/repo.bash_completion

Change-Id: I7ca5d7eba70244d875c48ce76c999c8a10b88934

From git.git, contrib/completion/git-completion.bash

Change-Id: Ic7eb3cb01b1831ec20a1d99dee15171f7c919d54

From Chromium [1]

[1] http://git.chromium.org/gitweb/?p=chromiumos/platform/dev-util.git;a=blob_plain;f=host/repo_bash_completion;hb=master

Change-Id: If246a455244505b26f854ba83d662341d9353592