Attempting to use zombie in node.js to load content into a dynamically created iframe. Doesn't seem to work. I am new to node.js — what am I doing wrong?

ahh_zombie.js

browser = require('zombie');
browser = new browser();
browser.visit('https://dl.dropboxusercontent.com/u/625330/iframe/index.html')
document = browser.document;
iframe = document.createElement('iframe');
document.body.appendChild(iframe)
iframe.onload = function () {
  console.log('loaded') // this does not happen
};
iframe.src = 'https://dl.dropboxusercontent.com/u/625330/iframe/frame.html';

// Trying the above commands in node I get:
// iframe.location.href --> 'https://dl.dropboxusercontent.com/u/625330/iframe/frame.html'
// iframe.contentDocument.readyState --> 'loading'
// iframe.contentDocument.body --> null
// Seems like it never loads

//I put some console.log calls in the compiled zombie code (in dom_iframe.js):

HTML.HTMLFrameElement.prototype._attrModified = function(name, value, oldValue) {
  var onload, url,
    _this = this;

  HTML.HTMLElement.prototype._attrModified.call(this, name, value, oldValue);
  if (name === "name") {
    return this.ownerDocument.parentWindow.__defineGetter__(value, function() {
      return _this.contentWindow;
    });
  } else if (name === "src" && value) {
    console.log('HEY THERE') // I see this
    url = HTML.resourceLoader.resolve(this.ownerDocument, value);
    this.contentWindow.location = url;
    onload = function() {
      console.log('I AM LOADED') // I never see this
      _this.contentWindow.removeEventListener("load", onload);
      onload = _this.ownerDocument.createEvent("HTMLEvents");
      onload.initEvent("load", true, false);
      return _this.dispatchEvent(onload);
    };
    return this.contentWindow.addEventListener("load", onload);
  }
};

Oh dear, I've been working too much. Of course the while loop is blocking everything. Also the iframe content page is "frame.html" not "iframe.html". Alright, so now if I do:

browser = require('zombie');
browser = new browser();
browser.debug = true;
browser.visit('https://dl.dropboxusercontent.com/u/625330/iframe/index.html', function () {
    console.log('page loaded, waiting for iframe to load...')
    document = browser.document;
    iframe = document.createElement('iframe');
    iframe.onload = function () {
        console.log('iframe loaded!')
    };
    iframe.src = 'https://dl.dropboxusercontent.com/u/625330/iframe/frame.html';
    document.body.appendChild(iframe)
})

I get:

Zombie: Opened window https://dl.dropboxusercontent.com/u/625330/iframe/index.html 
Zombie: GET https://dl.dropboxusercontent.com/u/625330/iframe/index.html => 200
Zombie: Loaded document https://dl.dropboxusercontent.com/u/625330/iframe/index.html
Zombie: Event loop is empty
page loaded, waiting for iframe to load...
Zombie: Opened window about:blank 
Zombie: Loaded document about:blank
Zombie: Opened window https://dl.dropboxusercontent.com/u/625330/iframe/frame.html 
Zombie: GET https://dl.dropboxusercontent.com/u/625330/iframe/frame.html => 200

But the onload doesn't fire. Using addEventListener('load'... also doesn't work.