old_contents: #!/usr/bin/env python
  # 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.
  
  from sharding_supervisor_old import *  # pylint: disable=W0401,W0614
  
  
  if __name__ == "__main__":
    sys.exit(main())
  
new_contents: #!/usr/bin/env python
  # 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.
  
  """Defer to run_test_cases.py."""
  
  import os
  import optparse
  import sys
  
  ROOT_DIR = os.path.dirname(
      os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
  
  
  def pop_gtest_output(args):
    """Extracts --gtest_output from the args if present."""
    for index, arg in enumerate(args):
      if arg.startswith('--gtest_output='):
        return args.pop(index)
  
  
  def main():
    parser = optparse.OptionParser()
  
    group = optparse.OptionGroup(
        parser, 'Compability flag with the old sharding_supervisor')
    group.add_option(
        '--no-color', action='store_true', help='Ignored')
    group.add_option(
        '--retry-failed', action='store_true', help='Ignored')
    group.add_option(
        '-t', '--timeout', type='int', help='Kept as --timeout')
    group.add_option(
        '--total-slaves', type='int', default=1, help='Converted to --index')
    group.add_option(
        '--slave-index', type='int', default=0, help='Converted to --shards')
    parser.add_option_group(group)
  
    parser.disable_interspersed_args()
    options, args = parser.parse_args()
  
    swarm_client_dir = os.path.join(ROOT_DIR, 'tools', 'swarm_client')
    sys.path.insert(0, swarm_client_dir)
  
    cmd = [
      '--shards', str(options.total_slaves),
      '--index', str(options.slave_index),
      '--no-dump',
      '--no-cr',
    ]
    if options.timeout is not None:
      cmd.extend(['--timeout', str(options.timeout)])
    gtest_output = pop_gtest_output(args)
    if gtest_output:
      # It is important that --gtest_output appears before the '--' so it is
      # properly processed by run_test_cases.
      cmd.append(gtest_output)
  
    import run_test_cases  # pylint: disable=F0401
  
    return run_test_cases.main(cmd + ['--'] + args)
  
  
  if __name__ == '__main__':
    sys.exit(main())
  
subject: Switch over to run_test_cases.py, take 2.