chromium/third_party/blink/web_tests/editing/selection/drag-text-delay.html

<!DOCTYPE html>
<html>
<body>
<p>On most platforms, if you click and move the mouse on selected text, it will always initiate a drag. On Mac, there must be a delay between the click and the mouse move before a drag starts. Otherwise, it will just change the selection.</p>
<p>To manually test, select "hello" and rapidly drag. You should see "hello world" on Mac and "worldhello" on all other platforms.</p>
<div id="log"></div>
<input id="text" type="text" value="hello world" />
<script>
if (window.testRunner) {
    testRunner.dumpAsText();

    var text = document.getElementById("text");
    text.focus();
    text.setSelectionRange(0, 5);

    var start_x = text.offsetLeft + 5;
    var start_y = text.offsetTop + text.offsetHeight / 2;
    eventSender.mouseMoveTo(start_x, start_y);
    eventSender.mouseDown();

    var end_x = text.offsetLeft + text.offsetWidth - 5;
    var end_y = start_y;
    eventSender.mouseMoveTo(end_x, end_y);
    eventSender.mouseUp();

    document.getElementById('log').innerText = text.value;
}
</script>
</body>
</html>