chromium/third_party/wpt_tools/wpt/tools/web_features/commands.json

{
  "web-features-manifest": {
    "path": "manifest.py",
    "script": "main",
    "parser": "create_parser",
    "help": "Create the WEB_FEATURES_MANIFEST.json",
    "virtualenv": true,
    "requirements": [
      "../metadata/yaml/requirements.txt"
    ]
  }
}