chromium/third_party/blink/web_tests/css3/filters/css-opacity-with-drop-shadow.html

<!DOCTYPE html>
<html>
<head>
    <title>This test verifies that an element's drop shadow filter is not clipped when a CSS opacity property is applied.</title>
    <!-- If the test passes, you should see a gray square and a light green square. -->
    <style>
        body {
            margin: 0;
        }
        #filtered {
            background-color: black;
            opacity: 0.5;
            filter: drop-shadow(110px 110px 0 #0f0);
            width: 100px;
            height: 100px;
        }
    </style>
</head>
<body>
    <div id="filtered"></div>
</body>