fallback-when-image-loading-disabled.html

<!DOCTYPE html>
<title>Fallback content should be shown when image loading is disabled</title>
<script>
  if (window.internals)
    internals.settings.setLoadsImagesAutomatically(false);
</script>
<body></body>
<script>
  let image = new Image();
  image.src = "resources/mu.png?" + Math.random();
  image.alt = "Chair spinning";
  document.body.appendChild(image);
</script>

chromium/third_party/blink/web_tests/images/fallback-when-image-loading-disabled.html