TEST=Rewrote the unit test to catch that case.

R=dpranke@chromium.org
BUG=

Review URL: http://codereview.chromium.org/7192010

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@89700 0039d316-1c4b-4281-b951-d872f2087c98