chromium/third_party/blink/web_tests/external/wpt/css/css-view-transitions/old-content-captures-opacity.html

<!DOCTYPE html>
<html class=reftest-wait>
<title>View transitions: capture opacity elements</title>
<link rel="help" href="https://drafts.csswg.org/css-view-transitions-1/">
<link rel="author" href="mailto:[email protected]">
<link rel="match" href="old-content-captures-opacity-ref.html">
<meta name=fuzzy content="maxDifference=0-1; totalPixels=0-50000">

<script src="/common/reftest-wait.js"></script>
<style>
.box {
  color: red;
  background: lightblue;
  width: 100px;
  height: 100px;
  contain: paint;
  position: absolute;
  font-size: 30pt;
}
#e1 { opacity: 0.75; top: 20px; left: 20px; view-transition-name: e1; }
#e2 { opacity: 0.5; top: 160px; left: 20px; view-transition-name: e2; }
#e3 { opacity: 0.25; top: 300px; left: 20px; view-transition-name: e3; }
div.dst { background: lightgreen; }
/* We're verifying what we capture, so just display the old contents for 5 minutes.  */
html::view-transition-group(*) { animation-duration: 300s; }
html::view-transition-new(*) { animation: unset; opacity: 0; }
html::view-transition-old(*) { animation: unset; opacity: 1; }
/* hide the root so we show transition background to ensure we're in a transition */
html::view-transition-group(root) { animation: unset; opacity: 0; }
html::view-transition { background: lightpink; }
</style>
<div id=e1 class=box>one</div>
<div id=e2 class=box>two</div>
<div id=e3 class=box>three</div>
<script>
failIfNot(document.startViewTransition, "Missing document.startViewTransition");

async function runTest() {
  document.startViewTransition(() => {
    e1.classList.add("dst");
    e2.classList.add("dst");
    e3.classList.add("dst");
    requestAnimationFrame(() => requestAnimationFrame(takeScreenshot));
  });
}
onload = () => requestAnimationFrame(() => requestAnimationFrame(runTest));
</script>