LayoutTests/media/modern-media-controls/scheduler/not-reentrant.html

<script src="../../../resources/js-test-pre.js"></script>
<script src="../../../../Source/WebCore/Modules/modern-media-controls/controls/scheduler.js" type="text/javascript"></script>
<script src="../resources/media-controls-utils.js" type="text/javascript"></script>
<script type="text/javascript">

description("This test checks that calling `scheduleLayout()` during a layout callback delays that callback until the next frame.");

window.jsTestIsAsync = true;

if (window.testRunner)
    window.testRunner.dumpAsText();

let numberOfFrames = 0;

scheduler.frameWillFire = function()
{
    debug(`Frame #${numberOfFrames} will fire`);
}

scheduler.frameDidFire = function()
{
    debug(`Frame #${numberOfFrames} fired`);

    numberOfFrames++;

    if (numberOfFrames === 2)
        finishMediaControlsTest();
};

function layout()
{
    debug(`layout() was called`);
    if (numberOfFrames !== 0)
        return;

    // This layout should not be performed right away but delayed until the
    // next frame since scheduleLayout() is not reentrant.
    debug(`scheduler.scheduleLayout(layout)`);
    scheduler.scheduleLayout(layout);
}

debug(`scheduler.scheduleLayout(layout)`);
scheduler.scheduleLayout(layout);

</script>
<script src="../../../resources/js-test-post.js"></script>