third_party/web_platform_tests/webmessaging/without-ports/028.html

<!doctype html>
<title>Cloning objects, preserving sharing #2</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<canvas id="a" width=30 height=30></canvas>
<div id=log></div>
<script>
async_test(function() {
  var canvas = document.getElementsByTagName("canvas")[0];
  var context = canvas.getContext("2d");
  var img_data = context.getImageData(0, 0, 30, 30);
  var obj = {a: img_data, b: {c: img_data, d: 3}};
  postMessage(obj, '*');
  onmessage = this.step_func(function(e) {
    assert_equals(e.data.a, e.data.b.c);
    this.done();
  });
});
</script>