Bot update!

scripts/slave/gclient_safe_revert.py

 #!/usr/bin/env python
 # Copyright (c) 2013 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.
 
 """Do a revert if a checkout exists."""
 
 import os
 import sys
 
 from common import chromium_utils
 
 
 def main():
   if len(sys.argv) != 3:
     print 'usage: gclient_safe_revert.py build_directory gclient_command'
     return 2
 
   build_directory = sys.argv[1]
   gclient_command = sys.argv[2]
 
   if not os.path.exists(build_directory):
     print 'Path %s doesn\'t exist, not running gclient.' % build_directory
     return 0
 
   if not os.path.isdir(build_directory):
     print 'Path %s isn\'t a directory, not running gclient.' % build_directory
     return 0
 
+  if os.path.isfile(os.path.join(build_directory, 'update.flag')):
+    print 'update.flag file found: bot_update has run and checkout is already '
+    print 'in a consistent state. No actions will be performed in this step.'
+    return 0
+
   gclient_config = os.path.join(build_directory, '.gclient')
   if not os.path.exists(gclient_config):
     print ('%s doesn\'t exist, not a gclient-controlled checkout.' %
               gclient_config)
     return 0
 
   # Work around http://crbug.com/280158
   cmd = [gclient_command, 'recurse', '-i', 'sh', '-c',
          'if [ -e .git ]; then git remote update; fi']
   chromium_utils.RunCommand(cmd, cwd=build_directory)
 
   cmd = [gclient_command, 'revert', '--nohooks', '--upstream']
   return chromium_utils.RunCommand(cmd, cwd=build_directory)
 
 
 if '__main__' == __name__:
   sys.exit(main())