1 files changed, 48 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/canvas/offscreen/manual/layers/unclosed-layers.w.html b/testing/web-platform/tests/html/canvas/offscreen/manual/layers/unclosed-layers.w.html
new file mode 100644
index 0000000000..a0014bb597
--- /dev/null
+++ b/testing/web-platform/tests/html/canvas/offscreen/manual/layers/unclosed-layers.w.html
@@ -0,0 +1,48 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<link rel="match" href="unclosed-layers-expected.html">
+<title>Canvas test: unclosed-layers</title>
+<h1>unclosed-layers</h1>
+<p class="desc">Check that unclosed layers aren't rendered.</p>
+<canvas id="canvas" width="1" height="1">
+  <p class="fallback">FAIL (fallback content)</p>
+</canvas>
+<script id='myWorker' type='text/worker'>
+  self.onmessage = msg => {
+    const offscreen = msg.data.canvas;
+    const ctx = offscreen.getContext('2d');
+    offscreen.width = offscreen.height = 200;
+
+    ctx.fillStyle = 'purple';
+    ctx.fillRect(60, 60, 75, 50);
+
+    ctx.beginLayer({filter: {name: 'dropShadow', dx: -2, dy: 2}});
+    ctx.fillRect(40, 40, 75, 50);
+    ctx.fillStyle = 'grey';
+    ctx.fillRect(50, 50, 75, 50);
+
+    self.postMessage('setup ready');
+  }
+</script>
+<script>
+  const blob = new Blob([document.getElementById('myWorker').textContent]);
+  const worker = new Worker(URL.createObjectURL(blob));
+  var placeholder = document.getElementById('canvas');
+  var offscreen = placeholder.transferControlToOffscreen();
+  worker.addEventListener('message', msg => {
+    if(msg.data == 'setup ready') {
+      function draw () {
+          // Wait until frame propagates.
+          if(placeholder.width != 1) {
+            document.documentElement.classList.remove("reftest-wait");
+          } else {
+            requestAnimationFrame(draw);
+          }
+      }
+      requestAnimationFrame(draw);
+    }
+  });
+  worker.postMessage({
+      canvas: offscreen
+  }, [offscreen]);
+</script>