Examine source code of Auto Refresh Pro Duarte

{
  "manifest_version": 2,
  "name": "Auto Refresh Pro",
  "version": "4.2",
  "permissions": [
    "tabs",
    "storage",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "autorefreshpro@example.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}