So pass a single item array. The presubmit checks would fail otherwise.

This code path was definitely not exercised by the unit tests. Unit tests are
left as an exercise to the reader.

TBR=vbendeb
BUG=none
TEST=none

Review URL: http://codereview.chromium.org/6479006

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@74396 0039d316-1c4b-4281-b951-d872f2087c98