PRESUBMIT: use "master." prefix in CQ_INCLUDE_TRYBOTS.

content/browser/frame_host/PRESUBMIT.py

 # Copyright 2016 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.
 """Presubmit script for //content/browser/frame_host.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into depot_tools.
 """
 
 import re
 
 
 def _GetTryMasters(project, change):
   return {
-    'tryserver.chromium.linux': {
+    'master.tryserver.chromium.linux': {
       'linux_site_isolation': [],
      },
   }
 
 
 def GetPreferredTryMasters(project, change):
   # TODO(nick, dcheng): Using the value of _GetTryMasters() instead of an empty
   # value here would cause 'git cl try' to include the site isolation trybots,
   # which would be nice. But it has the side effect of replacing, rather than
   # augmenting, the default set of try servers. Re-enable this when we figure
@@ skipping 18 matching lines @@
   new_description = description
   new_description += '\nCQ_INCLUDE_TRYBOTS=%s' % ';'.join(
       '%s:%s' % (master, ','.join(bots))
       for master, bots in masters.iteritems())
   results.append(output_api.PresubmitNotifyResult(
       'Automatically added site isolation trybots to run tests on CQ.'))
 
   rietveld_obj.update_description(issue, new_description)
 
   return results