title: document.readyState for a popup window is always "complete" in Chrome
body: <p>A simple test: if I open developer tools on this page and run this command in Chrome:</p>
  
  <pre><code>window.open('https://stackoverflow.com/', 'newWindowName').document.readyState
  </code></pre>
  
  <p>I see the output:</p>
  
  <blockquote>
    <p>"complete"</p>
  </blockquote>
  
  <p>which looks wrong to me since the window clearly didn't load yet. I see more sane output in other browsers - I checked Firefox and IE.</p>
  
  <p>My question is: is there any other way to be notified when a created window's DOM is ready in Chrome? It's not cross origin, so I should be able to access the window's properties. Also, I'm aware that there's the <code>DOMContentLoaded</code> event, but it fires only once, and doesn't work again if I re-use the same window (in my example, using the name "newWindowName") to get notified when a new page's DOM is ready.</p>