Examine source code of Barcode refresh icon

{
  "manifest_version": 2,
  "name": "Barcode refresh icon",
  "version": "1.0",
  "description": "The Refresh Barcode icon is typically designed to indicate the action of reloading, updating, or regenerating a new barcode.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Click me!"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{9eacc058-867e-4610-924f-7e83c4148dfe}"
    }
  }
}