text: #!/usr/bin/env python
  import os
  import sys
  from util import run
  
  root_path = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
  third_party_path = os.path.join(root_path, "third_party")
  depot_tools_path = os.path.join(third_party_path, "depot_tools")
  os.chdir(root_path)
  
  
  def download(fn):
      run([
          os.path.join(depot_tools_path + '/download_from_google_storage.py'),
          '--no_resume', '--platform=' + sys.platform, '--no_auth', '--bucket',
          'chromium-gn', '-s',
          os.path.join(root_path, fn)
      ],
          quiet=True)
  
  
  if sys.platform == 'win32':
      download("third_party/v8/buildtools/win/gn.exe.sha1")
  elif sys.platform == 'darwin':
      download("third_party/v8/buildtools/mac/gn.sha1")
  elif sys.platform.startswith('linux'):
      download("third_party/v8/buildtools/linux64/gn.sha1")
  run(['python', 'third_party/v8/tools/clang/scripts/update.py', '--if-needed'],
      quiet=True)
  