This simplifies future removals of unnecessary code from git-cl.

Bug: 770408
Change-Id: I20329fb6d93b349bf2e9f4aebc795b3f7ef0b646
Reviewed-on: https://chromium-review.googlesource.com/1070588
Commit-Queue: Aaron Gable <agable@chromium.org>
Reviewed-by: Marc-Antoine Ruel <maruel@chromium.org>