chromium/third_party/blink/web_tests/http/tests/media/video-controls-overflow-menu-download-button.html

<!DOCTYPE html>
<title>Clicking on the overflow download button should download media.</title>
<script src="../resources/testharness.js"></script>
<script src="../resources/testharnessreport.js"></script>
<script src="../../media-resources/media-controls.js"></script>
<script src="../../media-resources/overflow-menu.js"></script>
<!--Padding ensures the overflow menu is visible for the tests. -->
<body style="padding-top: 200px; padding-left: 100px">
<video controls></video>
<script>
if (window.testRunner) {
  testRunner.waitUntilExternalURLLoad();
}
async_test(function(t) {
  // Set up video
  var video = document.querySelector("video");
  video.src = "resources/test.ogv";
  video.setAttribute("width", "60");
  video.setAttribute("height", "100");
  enableTestMode(video);

  var controlID = "-internal-media-controls-download-button";
  var downloadButton = mediaControlsElement(internals.shadowRoot(video).firstChild, controlID);

  video.onloadeddata = t.step_func(function() {
    var overflowList = getOverflowList(video);
    var overflowMenu = getOverflowMenuButton(video);

    // Click on the overflow menu button
    var coords = elementCoordinates(overflowMenu);
    clickAtCoordinates(coords[0], coords[1]);

    // Click on download button
    var coords = elementCoordinates(overflowList.children[OverflowMenuButtons.DOWNLOAD]);
    clickAtCoordinates(coords[0], coords[1]);
  });
});
</script>
</body>