Examine source code of ezdark

{
  "manifest_version": 2,
  "name": "Darkside",
  "version": "1.0",
  "description": "Makes it dark.",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "darkside.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{013c51f9-b61e-41d2-aa11-4dae0c5608f7}"
    }
  }
}