I think this makes tests easier to read and write.

Change-Id: I9430a5d40e3466ff2a24b6b40253419aea3f30b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1820034Reviewed-by: Anthony Polito <apolito@google.com>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>