This is backwards compatible, and should be done prior
to upgrading repo's internals to 1.9.4.

BUG=chromium-os:31841
TEST=manual validation

Review URL: https://chromiumcodereview.appspot.com/10541155

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@142238 0039d316-1c4b-4281-b951-d872f2087c98