Examine source code of Rotate Tabs

{
  "manifest_version": 2,
  "name": "Rotate Tabs",
  "version": "1.7",
  "description": "Alterna abas e previne logoff.",
  "browser_specific_settings": {
    "gecko": {
      "id": "anderson.volpiano@gmail.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "tabs",
    "<all_urls>"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Tab Rotator",
    "default_icon": "default.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  }
}