Add setbotcommit method to gerrit_client

This is required if we want to land a bot-generated-cl.

BUG=1207955
TEST=e2e

Change-Id: Ib758b9782f9951a3ec23ce9970b0db2a48b1b5f2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3049573
Commit-Queue: Xinan Lin <linxinan@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@google.com>
Reviewed-by: Michael Moss <mmoss@chromium.org>

gerrit_client.py

@@ -265,6 +265,20 @@ def CMDgetcommitincludedin(parser, args):
   write_result(result, opt)
 
 
+@subcommand.usage('[args ...]')
+def CMDsetbotcommit(parser, args):
+  """Sets bot-commit+1 to a bot generated change."""
+  parser.add_option('-c', '--change', type=int, help='change number')
+  (opt, args) = parser.parse_args(args)
+  result = gerrit_util.SetReview(
+      urlparse.urlparse(opt.host).netloc,
+      opt.change,
+      labels={'Bot-Commit': 1},
+      ready=True)
+  logging.info(result)
+  write_result(result, opt)
+
+
 @subcommand.usage('')
 def CMDabandon(parser, args):
   """Abandons a Gerrit change."""

gerrit_util.py

@@ -921,7 +921,7 @@ def SetReview(host, change, msg=None, labels=None, notify=None, ready=None):
           int(response['labels'][key] != int(val))):
         raise GerritError(200, 'Unable to set "%s" label on change %s.' % (
             key, change))
-
+  return response
 
 def ResetReviewLabels(host, change, label, value='0', message=None,
                       notify=None):