Rewrite presubmit scripts to use new EnsureCQIncludeTrybotsAreAdded.

chrome/browser/win/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 chrome/browser/win.
 
 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 PostUploadHook(cl, change, output_api):
   """git cl upload will call this hook after the issue is created/modified.
 
   This hook adds extra try bots list to the CL description in order to run
   tests on the Windows 10 try bot in addition to CQ try bots.
   """
-  rietveld_obj = cl.RpcServer()
-  issue = cl.issue
-  description = rietveld_obj.get_description(issue)
-  if re.search(r'^CQ_INCLUDE_TRYBOTS=.*', description, re.M | re.I):
-    return []
-
-  bots = [
-    'master.tryserver.chromium.win:win10_chromium_x64_rel_ng',
-  ]
-
-  results = []
-  new_description = description
-  new_description += '\nCQ_INCLUDE_TRYBOTS=%s' % ';'.join(bots)
-  results.append(output_api.PresubmitNotifyResult(
-      'Automatically added Win10 bot to run on CQ.'))
-
-  if new_description != description:
-    rietveld_obj.update_description(issue, new_description)
-
-  return results
+  return output_api.EnsureCQIncludeTrybotsAreAdded(
+    cl,
+    [
+      'master.tryserver.chromium.win:win10_chromium_x64_rel_ng',
+    ],
+    'Automatically added Win10 bot to run on CQ.')