chromium/third_party/blink/web_tests/paint/selection/text-selection-drag.html

<!DOCTYPE html>
<html>
<head>
<script src="../../resources/ahem.js"></script>
<style>
body {
  color: green;
  font: 50px/1 Ahem;
}
</style>
<script>
function runTest() {
  if (!window.testRunner)
    return;

  testRunner.dumpDragImage();
  var selectMe = document.getElementById('selectMe');
  window.getSelection().selectAllChildren(selectMe);
  var x = selectMe.offsetLeft + selectMe.offsetWidth / 2;
  var y = selectMe.offsetTop + selectMe.offsetHeight / 2;
  eventSender.mouseMoveTo(x, y);
  eventSender.mouseDown();
  eventSender.leapForward(200);
  eventSender.mouseMoveTo(x + 50, y + 50);
  eventSender.mouseUp();
}
</script>
</head>
<body onload="runTest()">
<div id="selectMe">To run this test manually, select some text and drag it around. The text should not be drawn with halo outlines.</div>
</body>
</html>