third_party/WebKit/LayoutTests/fast/dom/HTMLImageElement/image-srcset-react-to-media-changes-when-viewport-downsized.html

   1 <!DOCTYPE html>
   2 <title>Test that does not load a low quality resource when viewport is downsized</title>
   3 <script src="../../../resources/testharness.js"></script>
   4 <script src="../../../resources/testharnessreport.js"></script>
   5 <iframe style="width: 120px;"></iframe>
   6 <script>
   7 async_test(function(t) {
   8     var iframe = document.querySelector('iframe');
   9     var iframeDoc = iframe.contentWindow.document;
  10
  11     document.body.offsetTop;
  12     iframeDoc.body.innerHTML = '<img id="srcset" srcset="resources/blue_rect.jpg 90w, resources/image-set-4x.png 120w">';
  13
  14     img = iframeDoc.getElementById('srcset');
  15
  16     var first = true;
  17     img.onload = t.step_func(function() {
  18         assert_true(first);
  19         first = false;
  20         assert_equals(img.currentSrc.indexOf("blue_rect.jpg"), -1);
  21
  22         iframe.style.width = '90px';
  23         requestAnimationFrame(function() {
  24             requestAnimationFrame(function() {
  25                 setTimeout(t.step_func(function() {
  26                     assert_equals(img.currentSrc.indexOf("blue_rect.jpg"), -1);
  27                     t.done();
  28                 }), 0);
  29             });
  30         });
  31     });
  32 });
  33 </script>