Examine source code of MediaTab

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "MediaTab",
  "description": "Shows tabs playing media",
  "options_ui": {
    "page": "settings/settings.html"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "@mediaTabExtension",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "browser_action": {
    "default_icon": "icons/icon.png",
    "default_title": "MediaTab",
    "default_popup": "popup/index.html"
  }
}