chromium/src/third_party/blink/web_tests/fast/events/mouse-up-preventDefault-dragstate.html

<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>

<style>
#target {
  width: 200px;
  height: 200px;
}
</style>

<p>This is the top level window.</p>
<p>Click somewhere. Move the mouse into the iframe.</p>
<p>Mouse move should be received by the iframe.</p>
<iframe id="target" srcdoc="
<p>This is the iframe.</p>
<script>
  document.addEventListener('mousemove', function() {
    parent.mouseMoveReceived();
  });
</script>
"></iframe>

<script>
var test_mousemove = async_test("Inner frame should receive mousemove even when mouseup preventDefault was called in the parent frame.");
var mouseUpPrevented = 0;
function mouseMoveReceived() {
  if (mouseUpPrevented == 1)
    test_mousemove.done();
}
document.addEventListener("mouseup", function(e) {
  e.preventDefault();
  mouseUpPrevented = 1;
});

function runTest() {
  if (window.eventSender) {
    var targetRect = document.getElementById("target").getBoundingClientRect();
    eventSender.mouseMoveTo(targetRect.right+10, targetRect.bottom+10);
    eventSender.mouseDown(0);
    eventSender.mouseUp(0);
    eventSender.mouseMoveTo(targetRect.right-10, targetRect.bottom-10);
  }
}
window.onload = function() {
  runTest();
}
</script>