This fix adds the crosbug.com shorturl scheme for the chromium-os project.

BUG=None
TEST=manual run of ./my_activity.py


Review URL: https://chromiumcodereview.appspot.com/12226135

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@182300 0039d316-1c4b-4281-b951-d872f2087c98