Examine source code of Old Google

{
  "manifest_version": 2,
  "name": "Old Google",
  "version": "3.1.5",
  "description": "Replaces the current Google logo on google.com and the search page to use the old 2010-2013 logo.",
  "browser_specific_settings": {
    "gecko": {
      "id": "{2c0af148-55d9-41e8-9df1-ed2dc90b2305}",
      "strict_min_version": "120.0"
    }
  },
  "icons": {
    "32": "resources/addon/32.png",
    "48": "resources/addon/48.png",
    "96": "resources/addon/96.png"
  },
  "web_accessible_resources": [
    "resources/google/nav.png",
    "resources/google/favicons/maps.ico",
    "resources/google/favicons/search.ico",
    "resources/google/favicons/search_alt.ico",
    "resources/google/favicons/finance.ico",
    "resources/google/favicons/scholar.ico",
    "resources/google/favicons/news.ico",
    "resources/google/favicons/earth.ico",
    "resources/google/logos/books.png",
    "resources/google/logos/finance_left.png",
    "resources/google/logos/finance_right.png",
    "resources/google/logos/g.png",
    "resources/google/logos/maps.png",
    "resources/google/logos/maps_watermark_mono.png",
    "resources/google/logos/maps_watermark.png",
    "resources/google/logos/news_left.png",
    "resources/google/logos/news.png",
    "resources/google/logos/news_right.png",
    "resources/google/logos/patents.png",
    "resources/google/logos/scholar.png",
    "resources/google/logos/search.png",
    "resources/google/logos/shopping_left.png",
    "resources/google/logos/shopping.png",
    "resources/google/logos/shopping_right.png",
    "resources/google/logos/trends.png",
    "resources/google/logos/videos.png",
    "resources/google/logos/earth.png"
  ],
  "browser_action": {
    "default_icon": "resources/addon/vector.svg",
    "default_popup": "config/popup.html"
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.google.ac/*",
        "*://*.google.ad/*",
        "*://*.google.ae/*",
        "*://*.google.al/*",
        "*://*.google.am/*",
        "*://*.google.as/*",
        "*://*.google.at/*",
        "*://*.google.az/*",
        "*://*.google.ba/*",
        "*://*.google.be/*",
        "*://*.google.bf/*",
        "*://*.google.bg/*",
        "*://*.google.bi/*",
        "*://*.google.bj/*",
        "*://*.google.bs/*",
        "*://*.google.bt/*",
        "*://*.google.by/*",
        "*://*.google.ca/*",
        "*://*.google.cat/*",
        "*://*.google.cc/*",
        "*://*.google.cd/*",
        "*://*.google.cf/*",
        "*://*.google.cg/*",
        "*://*.google.ch/*",
        "*://*.google.ci/*",
        "*://*.google.cl/*",
        "*://*.google.cm/*",
        "*://*.google.cn/*",
        "*://*.google.co.ao/*",
        "*://*.google.co.bw/*",
        "*://*.google.co.ck/*",
        "*://*.google.co.cr/*",
        "*://*.google.co.id/*",
        "*://*.google.co.il/*",
        "*://*.google.co.in/*",
        "*://*.google.co.jp/*",
        "*://*.google.co.ke/*",
        "*://*.google.co.kr/*",
        "*://*.google.co.ls/*",
        "*://*.google.co.ma/*",
        "*://*.google.co.mz/*",
        "*://*.google.co.nz/*",
        "*://*.google.co.pn/*",
        "*://*.google.co.th/*",
        "*://*.google.co.tz/*",
        "*://*.google.co.ug/*",
        "*://*.google.co.uk/*",
        "*://*.google.co.uz/*",
        "*://*.google.co.ve/*",
        "*://*.google.co.vi/*",
        "*://*.google.co.za/*",
        "*://*.google.co.zm/*",
        "*://*.google.co.zw/*",
        "*://*.google.com/*",
        "*://*.google.com.af/*",
        "*://*.google.com.ag/*",
        "*://*.google.com.ai/*",
        "*://*.google.com.ar/*",
        "*://*.google.com.au/*",
        "*://*.google.com.bd/*",
        "*://*.google.com.bh/*",
        "*://*.google.com.bn/*",
        "*://*.google.com.bo/*",
        "*://*.google.com.br/*",
        "*://*.google.com.bz/*",
        "*://*.google.com.co/*",
        "*://*.google.com.cu/*",
        "*://*.google.com.cy/*",
        "*://*.google.com.do/*",
        "*://*.google.com.ec/*",
        "*://*.google.com.eg/*",
        "*://*.google.com.et/*",
        "*://*.google.com.fj/*",
        "*://*.google.com.gh/*",
        "*://*.google.com.gi/*",
        "*://*.google.com.gt/*",
        "*://*.google.com.hk/*",
        "*://*.google.com.jm/*",
        "*://*.google.com.kh/*",
        "*://*.google.com.kw/*",
        "*://*.google.com.lb/*",
        "*://*.google.com.lc/*",
        "*://*.google.com.ly/*",
        "*://*.google.com.mm/*",
        "*://*.google.com.mt/*",
        "*://*.google.com.mx/*",
        "*://*.google.com.my/*",
        "*://*.google.com.na/*",
        "*://*.google.com.nf/*",
        "*://*.google.com.ng/*",
        "*://*.google.com.ni/*",
        "*://*.google.com.np/*",
        "*://*.google.com.om/*",
        "*://*.google.com.pa/*",
        "*://*.google.com.pe/*",
        "*://*.google.com.pg/*",
        "*://*.google.com.ph/*",
        "*://*.google.com.pk/*",
        "*://*.google.com.pr/*",
        "*://*.google.com.py/*",
        "*://*.google.com.qa/*",
        "*://*.google.com.sa/*",
        "*://*.google.com.sb/*",
        "*://*.google.com.sg/*",
        "*://*.google.com.sl/*",
        "*://*.google.com.sv/*",
        "*://*.google.com.tj/*",
        "*://*.google.com.tn/*",
        "*://*.google.com.tr/*",
        "*://*.google.com.tw/*",
        "*://*.google.com.ua/*",
        "*://*.google.com.uy/*",
        "*://*.google.com.vc/*",
        "*://*.google.com.vn/*",
        "*://*.google.cv/*",
        "*://*.google.cz/*",
        "*://*.google.de/*",
        "*://*.google.dj/*",
        "*://*.google.dk/*",
        "*://*.google.dm/*",
        "*://*.google.dz/*",
        "*://*.google.ee/*",
        "*://*.google.es/*",
        "*://*.google.fi/*",
        "*://*.google.fm/*",
        "*://*.google.fr/*",
        "*://*.google.ga/*",
        "*://*.google.ge/*",
        "*://*.google.gf/*",
        "*://*.google.gg/*",
        "*://*.google.gl/*",
        "*://*.google.gm/*",
        "*://*.google.gp/*",
        "*://*.google.gr/*",
        "*://*.google.gy/*",
        "*://*.google.hn/*",
        "*://*.google.hr/*",
        "*://*.google.ht/*",
        "*://*.google.hu/*",
        "*://*.google.ie/*",
        "*://*.google.im/*",
        "*://*.google.io/*",
        "*://*.google.iq/*",
        "*://*.google.is/*",
        "*://*.google.it/*",
        "*://*.google.je/*",
        "*://*.google.jo/*",
        "*://*.google.kg/*",
        "*://*.google.ki/*",
        "*://*.google.kz/*",
        "*://*.google.la/*",
        "*://*.google.li/*",
        "*://*.google.lk/*",
        "*://*.google.lt/*",
        "*://*.google.lu/*",
        "*://*.google.lv/*",
        "*://*.google.md/*",
        "*://*.google.me/*",
        "*://*.google.mg/*",
        "*://*.google.mk/*",
        "*://*.google.ml/*",
        "*://*.google.mn/*",
        "*://*.google.ms/*",
        "*://*.google.mu/*",
        "*://*.google.mv/*",
        "*://*.google.mw/*",
        "*://*.google.ne/*",
        "*://*.google.nl/*",
        "*://*.google.no/*",
        "*://*.google.nr/*",
        "*://*.google.nu/*",
        "*://*.google.pl/*",
        "*://*.google.pn/*",
        "*://*.google.ps/*",
        "*://*.google.pt/*",
        "*://*.google.ro/*",
        "*://*.google.rs/*",
        "*://*.google.ru/*",
        "*://*.google.rw/*",
        "*://*.google.sc/*",
        "*://*.google.se/*",
        "*://*.google.sh/*",
        "*://*.google.si/*",
        "*://*.google.sk/*",
        "*://*.google.sm/*",
        "*://*.google.sn/*",
        "*://*.google.so/*",
        "*://*.google.st/*",
        "*://*.google.td/*",
        "*://*.google.tg/*",
        "*://*.google.tk/*",
        "*://*.google.tl/*",
        "*://*.google.tm/*",
        "*://*.google.tn/*",
        "*://*.google.to/*",
        "*://*.google.tt/*",
        "*://*.google.vg/*",
        "*://*.google.vu/*",
        "*://*.google.ws/*"
      ],
      "js": [
        "src/common.js",
        "src/configurator.js",
        "src/replace.js",
        "src/main.js"
      ],
      "run_at": "document_start"
    }
  ]
}