LayoutTests/fast/webgpu/offscreen-canvas-worker-rgba16float.html

<!-- webkit-test-runner [ WebGPUHDREnabled=true ] -->
<!DOCTYPE html>
<html class="reftest-wait">
<head>
<meta charset="utf-8">
<meta name="fuzzy" content="maxDifference=0-2; totalPixels=0-10000">
<title>An rgba16float WebGPU OffscreenCanvas in a worker shows its frames in its placeholder</title>
<style>
  body { margin: 0; }
  canvas { position: absolute; top: 0; left: 0; }
</style>
</head>
<body>
  <canvas id="canvas" width="100" height="100"></canvas>
  <script>
    // The placeholder's layer shows the worker's WebGPU render buffer itself, as a canvas element's
    // layer does, rather than a copy read back from it.
    function done() {
      document.documentElement.classList.remove("reftest-wait");
    }

    const worker = new Worker("resources/offscreen-canvas-solid-color-worker.js");
    worker.onmessage = event => {
      if (event.data === "configured") {
        worker.postMessage({ color: { r: 0, g: 1, b: 0, a: 1 }, frames: 10 });
        return;
      }
      if (event.data === "rendered") {
        // Lets the last frame reach the compositor before the snapshot.
        requestAnimationFrame(() => requestAnimationFrame(done));
        return;
      }
      done();
    };
    worker.onerror = done;

    const offscreen = document.getElementById("canvas").transferControlToOffscreen();
    worker.postMessage({ canvas: offscreen, format: "rgba16float" }, [offscreen]);
  </script>
</body>
</html>