Make `git cl description` work for Gerrit

git_cl.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Copyright (C) 2008 Evan Martin <martine@danga.com>
 
 """A git-command for integrating reviews on Rietveld and Gerrit."""
 
 from distutils.version import LooseVersion
@@ skipping 2147 matching lines @@
 
   def GetMostRecentPatchset(self):
     data = self._GetChangeDetail(['CURRENT_REVISION'])
     return data['revisions'][data['current_revision']]['_number']
 
   def FetchDescription(self):
     data = self._GetChangeDetail(['COMMIT_FOOTERS', 'CURRENT_REVISION'])
     return data['revisions'][data['current_revision']]['commit_with_footers']
 
   def UpdateDescriptionRemote(self, description):
-    # TODO(tandrii)
-    raise NotImplementedError()
+    gerrit_util.SetCommitMessage(self._GetGerritHost(), self.GetIssue(),
+                                 description)
 
   def CloseIssue(self):
     gerrit_util.AbandonChange(self._GetGerritHost(), self.GetIssue(), msg='')
 
   def SubmitIssue(self, wait_for_merge=True):
     gerrit_util.SubmitChange(self._GetGerritHost(), self.GetIssue(),
                              wait_for_merge=wait_for_merge)
 
   def _GetChangeDetail(self, options=None, issue=None):
     options = options or []
@@ skipping 2634 matching lines @@
 if __name__ == '__main__':
   # These affect sys.stdout so do it outside of main() to simplify mocks in
   # unit testing.
   fix_encoding.fix_encoding()
   setup_color.init()
   try:
     sys.exit(main(sys.argv[1:]))
   except KeyboardInterrupt:
     sys.stderr.write('interrupted\n')
     sys.exit(1)