Support "--with_branch_heads" for unmanaged checkouts.

R=piman@chromium.org,maruel@chromium.org

Review URL: https://codereview.chromium.org/14178003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@194527 0039d316-1c4b-4281-b951-d872f2087c98

gclient_scm.py

@@ -290,6 +290,7 @@ class GitWrapper(SCMWrapper):
       return
 
     if not managed:
+      self._UpdateBranchHeads(options, fetch=False)
       self.UpdateSubmoduleConfig()
       print ('________ unmanaged solution; skipping %s' % self.relpath)
       return