git-cl-try: print proper access denied error msg

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."""
 
 from distutils.version import LooseVersion
@@ skipping 234 matching lines @@
   try_count = 0
   while True:
     response, content = http.request(*args, **kwargs)
     try:
       content_json = json.loads(content)
     except ValueError:
       content_json = None
 
     # Buildbucket could return an error even if status==200.
     if content_json and content_json.get('error'):
+      error = content_json.get('error')
+      if error.get('code') == 403:
+        raise BuildbucketResponseException(
+            'Access denied: %s' % error.get('message', ''))
       msg = 'Error in response. Reason: %s. Message: %s.' % (
-          content_json['error'].get('reason', ''),
-          content_json['error'].get('message', ''))
+          error.get('reason', ''), error.get('message', ''))
       raise BuildbucketResponseException(msg)
 
     if response.status == 200:
       if not content_json:
         raise BuildbucketResponseException(
             'Buildbucket returns invalid json content: %s.\n'
             'Please file bugs at http://crbug.com, label "Infra-BuildBucket".' %
             content)
       return content_json
     if response.status < 500 or try_count >= 2:
@@ skipping 3693 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()
   colorama.init()
   try:
     sys.exit(main(sys.argv[1:]))
   except KeyboardInterrupt:
     sys.stderr.write('interrupted\n')
     sys.exit(1)