Examine source code of Direct - Screen Sharing

{
  "manifest_version": 2,
  "name": "Direct",
  "version": "1.1resigned1",
  "description": "Adds a red border to all webpages matching mozilla.org.",
  "content_scripts": [
    {
      "matches": [
        "*://*.wmdirect.com.br/*"
      ],
      "js": [
        "index.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{20e7a872-e071-43b7-87f8-fd84a632f1f8}"
    }
  }
}