This is a reland of 50c6d8d3

Original change's description:
> Print ps in intervals while the process is running
>
> R=apolito@google.com, ehmaldonado@chromium.org
>
> Bug: 1074355
> Change-Id: Id2d5c8ca6f27fefb0fe8d769ae2e50dbaaddadbb
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2167221
> Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
> Reviewed-by: Anthony Polito <apolito@google.com>
> Commit-Queue: Josip Sokcevic <sokcevic@google.com>

R=apolito@google.com, ehmaldonado@chromium.org

Bug: 1074355
Change-Id: I488b521e4a3b859c37f0bb1e21cad7d037f8f97e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2169392Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>