Examine source code of Quick Zoom v2

{
  "manifest_version": 2,
  "name": "Quick Zoom",
  "version": "1.0",
  "description": "Quickly adjust the zoom level of the current webpage.",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/zoom-48.png"
    }
  },
  "icons": {
    "48": "icons/zoom-48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{16118272-17ee-4fa6-bfc9-ddffb3391a4e}"
    }
  }
}