Add automatic retry mechanism and LKGR support.

PRESUBMIT.py

 # Copyright (c) 2011 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.
 
 """Top-level presubmit script for commit-queue.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts for
 details on the presubmit API built into gcl.
 """
 
 import os
 
 
 def CommonChecks(input_api, output_api):
   output = []
   black_list = list(input_api.DEFAULT_BLACK_LIST) + [
       r'^workdir/.*',
-      r'^thirdparty/.*'
   ]
   output.extend(input_api.canned_checks.RunPylint(
       input_api, output_api, black_list=black_list))
   output.extend(RunUnittests(input_api, output_api))
   return output
 
 
 def CheckChangeOnUpload(input_api, output_api):
   return CommonChecks(input_api, output_api)
 
 
 def CheckChangeOnCommit(input_api, output_api):
   return CommonChecks(input_api, output_api)
 
 
 def RunUnittests(input_api, output_api):
   out = []
   path = input_api.os_path.join(input_api.PresubmitLocalPath(), 'tests')
   for item in os.listdir(path):
     if not item.endswith('test.py'):
       continue
     proc = input_api.subprocess.Popen([
         input_api.os_path.join('tests', item), '-q'])
     proc.communicate()
     if proc.returncode:
       out.append(output_api.PresubmitError('Unit test %s failed' % item))
   return out