This is in order to support 'features' like got_revision for build systems
unwilling to scrape the human-readable output of gclient in order to extract
basic information :)

R=agable@chromium.org, maruel@chromium.org
BUG=265618

Review URL: https://chromiumcodereview.appspot.com/23753008

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@225046 0039d316-1c4b-4281-b951-d872f2087c98