A new-line token is being added on Python 3, so add it explicitly
so that it also appears on Python 2.

Bug: 984182
Change-Id: I3bfb6ca83d94b6a3452b938f35f5a3174fe85903
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1764465Reviewed-by: Marc-Antoine Ruel <maruel@chromium.org>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>