Requires https://codereview.chromium.org/779883002/ to be landed/rolled before it's useful.

R=dpranke@chromium.org
BUG=348474

Review URL: https://codereview.chromium.org/779513005

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@293269 0039d316-1c4b-4281-b951-d872f2087c98