Examine source code of Extension Listes

{
  "manifest_version": 2,
  "name": "Extension Lister",
  "version": "1.0",
  "description": "Displays a list of all installed extensions.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "permissions": [
    "management"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{41014111-c4cd-4706-b7fd-48b00c210af5}"
    }
  }
}