Examine source code of toQR

{
  "manifest_version": 2,
  "name": "toQR",
  "author": "rex+_+",
  "short_name": "toQR",
  "version": "1.1resigned1",
  "description": "Convert the current page's URL to QR Code,\nSo that you can scan using your mobile device and continue reading from where you left off.\nNo need for writing down the URL or copy and send it to your device.\n\nJust click... scan... & GO!!!",
  "icons": {
    "16": "icons/toQR.svg",
    "19": "icons/toQR.svg",
    "32": "icons/toQR.svg",
    "38": "icons/toQR.svg",
    "128": "icons/toQR.svg"
  },
  "permissions": [
    "tabs",
    "activeTab"
  ],
  "page_action": {
    "default_icon": {
      "16": "icons/toQR.svg",
      "19": "icons/toQR.svg",
      "32": "icons/toQR.svg",
      "38": "icons/toQR.svg",
      "128": "icons/toQR.svg"
    },
    "default_title": "toQR",
    "default_popup": "html/popup.html"
  },
  "background": {
    "page": "html/background.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{bd400d31-ab65-4387-b1f6-20b417cf089f}"
    }
  }
}