This is a reland of 968b1fe7

Original change's description:
> [git-cl] Use owners client when processing --[tb]r-owners.
>
> Change-Id: Id094bce2aa731359cd8af16f10ce79ae7e02bd85
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2572809
> Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
> Auto-Submit: Edward Lesmes <ehmaldonado@chromium.org>
> Reviewed-by: Josip Sokcevic <sokcevic@google.com>

Change-Id: I9f93d755b10517c5296f7095f735ec2295be34e9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2632840
Auto-Submit: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>
Reviewed-by: Josip Sokcevic <sokcevic@google.com>