This is purely so I can land:
https://chromium-review.googlesource.com/c/chromium/src/+/1625812
instead of:
https://chromium-review.googlesource.com/c/chromium/src/+/1625813

That is, the former is a slightly cleaner version of the latter. However,
it doesn't work w/o this patch.

Bug: 947531
Change-Id: If8e7f8080ba5f40408680b598fed511df89be8bb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1626479Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>