Add git cl format presubmit warning for extension and apps.

chrome/common/extensions/PRESUBMIT.py

 # 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.
 
 """Presubmit script for changes affecting extensions.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into gcl.
 """
 import fnmatch
@@ skipping 135 matching lines @@
     results.append(output_api.PresubmitError('IntegrationTest failed!'))
 
   # TODO(kalman): Re-enable this check, or decide to delete it forever. Now
   # that we have multiple directories it no longer works.
   # See http://crbug.com/297178.
   #_CheckLinks(input_api, output_api, results)
 
   return results
 
 def CheckChangeOnUpload(input_api, output_api):
-  return _CheckChange(input_api, output_api)
+  results = []
+  results += input_api.canned_checks.CheckPatchFormatted(input_api, output_api)
+  results += _CheckChange(input_api, output_api)
+  return results
 
 def CheckChangeOnCommit(input_api, output_api):
   return _CheckChange(input_api, output_api)