Examine source code of &udm=14

{
  "manifest_version": 2,
  "name": "&udm=14",
  "version": "1",
  "description": "Switches Google searches to the web tab",
  "icons": {
    "128": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.google.com/search*",
        "*://www.google.com/"
      ],
      "js": [
        "redir.js"
      ]
    }
  ],
  "chrome_settings_overrides": {
    "search_provider": {
      "name": "udm=14",
      "search_url": "https://www.google.com/search?udm=14&q={searchTerms}",
      "keyword": "disc",
      "favicon_url": "https://www.google.com/favicon.ico",
      "is_default": true,
      "encoding": "UTF-8"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "udm14@script-js.repl.co"
    }
  }
}