<!DOCTYPE html>
<title>Data URI document.contentType === 'text/html' when data URI MIME type is set</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<div id=log></div>
<script>
async_test(function() {
  var iframe = document.createElement('iframe');
  self.onmessage = this.step_func_done(e => {
    assert_equals(e.data, "text/html");
  });
  iframe.src = "data:text/html;charset=utf-8,<!DOCTYPE html><script>parent.postMessage(document.contentTy