LayoutTests/compositing/shared-backing/remove-sharing-layer.html

<!DOCTYPE html>
<html>
<head>
    <title>Tests that there is no crash when a sharing layer is removed.</title>
    <style>
    .trigger {
        position: absolute;
        top: 0;
        left: 0;
        height: 100px;
        width: 100px;
        background-color: silver;
        transform: translateZ(0);
    }

    .absolute {
        position: absolute;
        top: 50px;
        left: 50px;
        width: 200px;
        height: 200px;
        background: gray;
    }
    
    .inner {
        filter: drop-shadow(black 0 0 5px);
        margin: 10px;
        width: 100px;
        height: 100px;
        background-color: blue;
    }

    .inner.changed {
        filter: none;
    }

    </style>
    <script>
        if (window.testRunner) {
            testRunner.dumpAsText();
            testRunner.waitUntilDone();
        }

        function doTest()
        {
            setTimeout(() => {
                document.getElementById('target').classList.add('changed');
                if (window.testRunner)
                    testRunner.notifyDone();
            }, 0);
        }
        window.addEventListener('load', doTest, false);
    </script>
</head>
<body>
    <p>This test should not crash or assert.</p>
    <div class="trigger"></div>
    <div class="absolute">
        <div id="target" class="inner"></div>
    </div>
</body>
</html>