Assume 'master' when remote branch not specified.

apply_issue.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.
 
 """Applies an issue from Rietveld.
 """
 
 import getpass
 import json
@@ skipping 143 matching lines @@
             options.issue, options.patchset,
             options.server, options.issue)
     return 1
   for patch in patchset.patches:
     print(patch)
   full_dir = os.path.abspath(options.root_dir)
   scm_type = scm.determine_scm(full_dir)
   if scm_type == 'svn':
     scm_obj = checkout.SvnCheckout(full_dir, None, None, None, None)
   elif scm_type == 'git':
-    scm_obj = checkout.GitCheckout(full_dir, None, None, None, None,
-                                   base_ref=options.base_ref,)
+    scm_obj = checkout.GitCheckout(root_dir=full_dir,
+                                   project_name=None,
+                                   remote_branch='master',
+                                   git_url=None,
+                                   commit_user=None,
+                                   base_ref=options.base_ref,
+                                   post_processors=None)
   elif scm_type == None:
     scm_obj = checkout.RawCheckout(full_dir, None, None)
   else:
     parser.error('Couldn\'t determine the scm')
 
   # TODO(maruel): HACK, remove me.
   # When run a build slave, make sure buildbot knows that the checkout was
   # modified.
   if options.root_dir == 'src' and getpass.getuser() == 'chrome-bot':
     # See sourcedirIsPatched() in:
@@ skipping 40 matching lines @@
               f, options.revision_mapping)
           annotated_gclient.emit_buildprops(revisions)
 
         return retcode
   return 0
 
 
 if __name__ == "__main__":
   fix_encoding.fix_encoding()
   sys.exit(main())