Is XMLHttpRequest responseType=“document” supported in Google Chrome?

Question

Information on Can I Use says that Chrome supports XMLHttpRequest Level 2.
I used example from MDC in my Chrome extension:

var xhr = new XMLHttpRequest();
xhr.onload = function() {
  alert(this.responseXML.title);
}
xhr.open("GET", url);
xhr.responseType = "document";
xhr.send();

However, xhr.response and xhr.responseXML are both null in onload (status is 200 OK).
Is this supported in Chrome and where people actually look to find out whether it is?