Add a unit test to catch potential regressions. Remove an old test new code broke.

TEST=unit tests
BUG=none

Review URL: http://codereview.chromium.org/6613025

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@76805 0039d316-1c4b-4281-b951-d872f2087c98