Examine source code of Scrapbook Helper

{
  "manifest_version": 2,
  "name": "Scrapbook Helper",
  "version": "1.2",
  "description": "SFGame scrapbook helper",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "tabs",
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "errorcek1@gmail.com"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.sfgame.cz/*",
        "*://*.sfgame.net/*",
        "*://*.sfgame.eu/*",
        "*://*.sfgame.de/*",
        "*://*.sfgame.pl/*",
        "*://*.sfgame.hu/*",
        "*://*.sfgame.ae/*",
        "*://*.sfgame.br/*",
        "*://*.sfgame.ca/*",
        "*://*.sfgame.cl/*",
        "*://*.sfgame.dk/*",
        "*://*.sfgame.es/*",
        "*://*.sfgame.fr/*",
        "*://*.sfgame.co.uk/*",
        "*://*.sfgame.gr/*",
        "*://*.sfgame.in/*",
        "*://*.sfgame.it/*",
        "*://*.sfgame.jp/*",
        "*://*.sfgame.mx/*",
        "*://*.sfgame.nl/*",
        "*://*.sfgame.pt/*",
        "*://*.sfgame.ro/*",
        "*://*.sfgame.ru/*",
        "*://*.sfgame.se/*",
        "*://*.sfgame.sk/*",
        "*://*.sfgame.tr/*",
        "*://*.sfgame.us/*",
        "*://sfgame.net/*"
      ],
      "js": [
        "pageload.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js",
      "playeritems.js",
      "scrapbook.js"
    ],
    "persistent": true
  }
}