LayoutTests/media/modern-media-controls/layout-node/visible.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="../../../../Source/WebCore/Modules/modern-media-controls/controls/layout-node.js" type="text/javascript"></script>
<script src="../resources/media-controls-utils.js" type="text/javascript"></script>
<script type="text/javascript">

description("Testing the <code>LayoutNode.visible</code> property.");

window.jsTestIsAsync = true;

const node = new LayoutNode;

debug("Checking default value");
shouldBe("node.visible", "true");
shouldBeEqualToString("node.element.style.display", "");

debug("");
debug("node.visible = false");
node.visible = false;
shouldBe("node.visible", "false");
shouldBeEqualToString("node.element.style.display", "");

let numberOfFrames = 0;
scheduler.frameDidFire = function()
{
    debug("");
    debug("Layout was performed");

    switch (++numberOfFrames) {
    case 1:
        shouldBe("node.visible", "false");
        shouldBeEqualToString("node.element.style.display", "none");
        debug("");
        debug("node.visible = true");
        node.visible = true;
        break;
    case 2:
        shouldBe("node.visible", "true");
        shouldBeEqualToString("node.element.style.display", "");

        debug("");
        debug("node.visible = true");
        node.visible = true;
        shouldBeFalse("scheduler.hasScheduledLayoutCallbacks");
        debug("");

        finishMediaControlsTest();
        break;
    }
};

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