The effect of this is to preserve the behavior of `git status`,
i.e., only changes in the top-level repository will be reported.

Updated test expectations; I have no idea what I'm doing.

Review URL: https://chromiumcodereview.appspot.com/10454088

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@140396 0039d316-1c4b-4281-b951-d872f2087c98