Examine source code of Export Cookies

{
  "manifest_version": 2,
  "name": "Export Cookies",
  "version": "0.3.2",
  "description": "Exports cookies to a Netscape format cookies.txt file.",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "author": "Rotem Dan",
  "homepage_url": "https://github.com/rotemdan/ExportCookies",
  "background": {
    "scripts": [
      "browser-polyfill.js",
      "libs/psl.js",
      "common.js",
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Export cookies",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "64": "icons/icon-64.png"
    }
  },
  "permissions": [
    "storage",
    "cookies",
    "downloads",
    "tabs",
    "<all_urls>"
  ]
}