<!doctype html>
<link rel="help" href="https://drafts.csswg.org/cssom-view/#dom-window-devicepixelratio">
<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1602347">
<link rel="author" href="mailto:emilio@crisal.io" title="Emilio Cobos Álvarez">
<link rel="author" href="https://mozilla.org" title="Mozilla">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<title>window.devicePixelRatio in an undisplayed iframe matches the dpi of the parent document</title>
<div style="display: none">
  <iframe src="about:blank"></iframe>
</div>
<script>
onload = function() {
  test(function() {
    let win = document.querySelector("iframe").contentWindow;
    assert_equals(win.devicePixelRatio, window.devicePixelRatio, "window.devicePixelRatio in an undisplayed iframe matches the dpi of the parent document");
  });
};
</script>