如何通过 js 修改微信浏览器的title?

document.setTitle = function(t) {
  document.title = t;
  var i = document.createElement('iframe');
  i.src = '/favicon.ico';
  i.style.display = 'none';
  i.onload = function() {
    setTimeout(function(){
      i.remove();
    }, 9)
  }
  document.body.appendChild(i);
}