This is especially useful when you want to do something like:

git try -s third_party/WebKit

from the chromium root checkout.

R=dpranke@chromium.org
BUG=

Review URL: https://chromiumcodereview.appspot.com/17703003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@210409 0039d316-1c4b-4281-b951-d872f2087c98