Examine source code of Show ASNumber

{
  "manifest_version": 2,
  "name": "Show ASNumber",
  "version": "0.6.0",
  "description": "Show information about the source AS Number of all visited sites.",
  "icons": {
    "64": "icons/ip.png",
    "128": "icons/ip_128.png"
  },
  "page_action": {
    "default_icon": "icons/ip.png",
    "default_title": "Show ASNumber",
    "default_popup": "popup.html"
  },
  "permissions": [
    "webRequest",
    "<all_urls>",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5bca8a29-0f10-4755-a44a-081a96c0e796}"
    }
  }
}