LayoutTests/http/tests/animations/threaded-animations-timeline-resumption-from-page-cache.html

<!-- webkit-test-runner [ UsesBackForwardCache=true ] -->
<style>

@keyframes slide {
    to { translate: 100px }
}

#target {
    width: 100px;
    height: 100px;
    background-color: black;
    animation: slide 1000s;
}
</style>

<div id="target"></div>
<div id="results">FAIL</div>

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

window.testRunner?.dumpAsText();
window.testRunner?.waitUntilDone();

document.addEventListener("visibilitychange", async () => {
    // As the document is resumed from the back-forward cache,
    // wait for the threaded animation to be committed for success.
    await UIHelper.renderingUpdate();
    document.getElementById("results").textContent = "PASS";
    window.testRunner?.notifyDone();
});

const path = 'animations/resources/threaded-animations-timeline-resumption-from-page-cache-helper.html';
const url = `${window.location.protocol}//localhost:${window.location.port}/${path}`;

(async function() {
    // As the document initially loads, wait for the threaded animation to be committed
    // and then navigate to a document on a separate domain such that the Web Process is
    // swapped. That document will immediately navigate back to this document.
    await UIHelper.renderingUpdate();
    window.location.href = url;
})();

</script>