Examine source code of Autorefresh on Error

{
  "description": "Autorefreshes page after 3 seconds if page did not load.",
  "manifest_version": 2,
  "name": "Autorefresh on Error",
  "version": "1.0",
  "permissions": [
    "webRequest",
    "tabs",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  }
}