Examine source code of Wordpress Toolbar

{
  "name": "__MSG_appName__",
  "description": "__MSG_appDesc__",
  "default_locale": "en",
  "version": "61.3resigned1",
  "manifest_version": 2,
  "background": {
    "page": "background.html"
  },
  "browser_action": {
    "default_icon": {
      "19": "images/icon19.png",
      "38": "images/icon38.png"
    }
  },
  "icons": {
    "16": "images/icon16.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "permissions": [
    "tabs",
    "storage",
    "management",
    "activeTab",
    "downloads",
    "contextMenus",
    "<all_urls>",
    "http://*/*",
    "https://*/*",
    "cookies"
  ],
  "web_accessible_resources": [
    "setup/*",
    "style/*"
  ],
  "applications": {
    "gecko": {
      "id": "{e8754cd5-4214-41ea-8e28-142af83d76b1}"
    }
  }
}