我正在尝试在Chrome扩展程序的内容脚本中加载Firebase:
var script = document.createElement("script")
script.type = "text/javascript"
script.src = "https://cdn.firebase.com/js/client/1.1.2/firebase.js"
document.body.appendChild(script)
firebaseUrl = 'https://foobar.firebaseio.com'
root = new Firebase(firebaseUrl)
但是我收到了错误信息:
Uncaught ReferenceError: Firebase is not defined
我做错了什么?