old_contents: #!/usr/bin/env python
  
  from __future__ import print_function
  
  import argparse
  import os
  import re
  import subprocess
  import sys
  
  SOURCE_ROOT = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
  
  
  def main():
    args = parse_args()
  
    chromedriver_name = {
      'darwin': 'chromedriver',
      'win32': 'chromedriver.exe',
      'linux2': 'chromedriver'
  }
  
    chromedriver_path = os.path.join(
      args.source_root, args.build_dir, chromedriver_name[sys.platform])
    proc = subprocess.Popen([chromedriver_path],
                            stdout=subprocess.PIPE, universal_newlines=True)
    try:
      output = proc.stdout.readline()
    except KeyboardInterrupt:
      returncode = 0
    finally:
      proc.terminate()
  
    returncode = 0
    match = re.search(
      '^Starting ChromeDriver [0-9]+.[0-9]+.[0-9]+.[0-9]+ .* on port [0-9]+$', output)
  
    if match == None:
      returncode = 1
  
    if returncode == 0:
      print('ok ChromeDriver is able to be initialized.')
  
    return returncode
  
  
  def parse_args():
      parser=argparse.ArgumentParser(description='Test ChromeDriver')
      parser.add_argument('--source-root',
                          default=SOURCE_ROOT,
                          required=False)
      parser.add_argument('--build-dir',
                          default=None,
                          required=True)
      return parser.parse_args()
  
  
  if __name__ == '__main__':
      sys.exit(main())
  
new_contents: #!/usr/bin/env python
  
  from __future__ import print_function
  
  import argparse
  import os
  import re
  import subprocess
  import sys
  
  SOURCE_ROOT = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
  
  
  def main():
    args = parse_args()
  
    chromedriver_name = {
      'darwin': 'chromedriver',
      'win32': 'chromedriver.exe',
      'linux2': 'chromedriver'
  }
  
    chromedriver_path = os.path.join(
      args.source_root, args.build_dir, chromedriver_name[sys.platform])
    proc = subprocess.Popen([chromedriver_path],
                            stdout=subprocess.PIPE, universal_newlines=True)
    try:
      output = proc.stdout.readline()
    except KeyboardInterrupt:
      returncode = 0
    finally:
      proc.terminate()
  
    returncode = 0
    match = re.search(
      '^Starting ChromeDriver [0-9]+.[0-9]+.[0-9]+.[0-9]+ .* on port [0-9]+$', output)
  
    if match is None:
      returncode = 1
  
    if returncode == 0:
      print('ok ChromeDriver is able to be initialized.')
  
    return returncode
  
  
  def parse_args():
      parser=argparse.ArgumentParser(description='Test ChromeDriver')
      parser.add_argument('--source-root',
                          default=SOURCE_ROOT,
                          required=False)
      parser.add_argument('--build-dir',
                          default=None,
                          required=True)
      return parser.parse_args()
  
  
  if __name__ == '__main__':
      sys.exit(main())
  
subject: change `== None` to `is None` (#25202)