Examine source code of eBay Seller Location

{
  "manifest_version": 2,
  "minimum_chrome_version": "21",
  "name": "eBay Seller Location",
  "description": "Add's the seller's real location to eBay item pages.",
  "version": "1.1",
  "content_scripts": [
    {
      "matches": [
        "http://*.ebay.com/itm/*",
        "https://*.ebay.com/itm/*",
        "http://*.ebay.co.uk/itm/*",
        "https://*.ebay.co.uk/itm/*",
        "http://*.ebay.com.au/itm/*",
        "https://*.ebay.com.au/itm/*",
        "http://*.ebay.at/itm/*",
        "https://*.ebay.at/itm/*",
        "http://*.ebay.be/itm/*",
        "https://*.ebay.be/itm/*",
        "http://*.ebay.ca/itm/*",
        "https://*.ebay.ca/itm/*",
        "http://*.ebay.com.hk/itm/*",
        "https://*.ebay.com.hk/itm/*",
        "http://*.ebay.fr/itm/*",
        "https://*.ebay.fr/itm/*",
        "http://*.ebay.de/itm/*",
        "https://*.ebay.de/itm/*",
        "http://*.ebay.in/itm/*",
        "https://*.ebay.in/itm/*",
        "http://*.ebay.ie/itm/*",
        "https://*.ebay.ie/itm/*",
        "http://*.ebay.it/itm/*",
        "https://*.ebay.it/itm/*",
        "http://*.ebay.com.my/itm/*",
        "https://*.ebay.com.my/itm/*",
        "http://*.ebay.nl/itm/*",
        "https://*.ebay.nl/itm/*",
        "http://*.ebay.ph/itm/*",
        "https://*.ebay.ph/itm/*",
        "http://*.ebay.pl/itm/*",
        "https://*.ebay.pl/itm/*",
        "http://*.ebay.com.sg/itm/*",
        "https://*.ebay.com.sg/itm/*",
        "http://*.ebay.es/itm/*",
        "https://*.ebay.es/itm/*",
        "http://*.ebay.ch/itm/*",
        "https://*.ebay.ch/itm/*"
      ],
      "js": [
        "content_scripts/jquery-3.3.1.min.js",
        "content_scripts/add_location.js"
      ],
      "run_at": "document_end"
    }
  ],
  "permissions": [
    "activeTab"
  ],
  "applications": {
    "gecko": {
      "id": "ebaysellerlocation@foo.bar",
      "strict_min_version": "52.0"
    }
  }
}