Codebase Browser
chromium
Go to App

chromium/third_party/blink/web_tests/accessibility/animated-image-loaded-events.html 

<!DOCTYPE html>
<script src="../resources/testharness.js"></script>
<script src="../resources/testharnessreport.js"></script>

<img id="img">

<script>
async_test(function(t) {
    var img = document.getElementById("img");
    var axImg = accessibilityController.accessibleElementById("img");
    var count = 0;
    axImg.addNotificationListener((notification) => {
        if (notification == "MarkDirty") {
            count++;
            // We should only get at most one notification.
            assert_equals(1, count);
        }
    });
    img.src = "../images/resources/animated2.gif";

    setTimeout(() => {
        assert_equals(1, count);
        t.done();
    }, 300);
}, "When loading an animated image, a notification is only received once.");
</script>