Examine source code of Google Page Speed Checker

{
  "manifest_version": 2,
  "name": "Google Page Speed Checker",
  "version": "1.0",
  "description": "This extension checks if the website being accessed has a Google PageSpeed score of 90 or higher.",
  "permissions": [
    "<all_urls>",
    "notifications"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "SpeedChecker@mail.com"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  }
}