chromium/third_party/blink/web_tests/http/tests/security/offscreencanvas-read-blocked-no-crossorigin.html

<!DOCTYPE html>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script>

function verifyOffscreenCanvasTaintedThenDone(offscreen, t) {
  assert_throws_dom("SecurityError", function() {
    offscreen.getContext("2d").getImageData(0, 0, 1, 1);
  }, "Check getImageData blocked.");
  offscreen.convertToBlob().then(
    function() {
      assert_unreached("Promise returned by convertToBlob was resolved.");
      t.done();
    },
    rejectionValue => {
      assert_equals(rejectionValue.name, "SecurityError");
      t.done();
    }
  );
}

async_test(t => {
  var image = new Image();
  // Notice that we don't set the image.crossOrigin property.
  image.src = "http://localhost:8000/security/resources/abe-allow-star.php";
  image.onload = function() {
    var offscreen = new OffscreenCanvas(10, 10);
    var ctx = offscreen.getContext('2d');
    ctx.drawImage(image, 0, 0);
    t.step(function() {
      verifyOffscreenCanvasTaintedThenDone(offscreen, t);
    });
  }
}, "Verify that an OffscreenCanvas tainted with cross-origin content cannot be read.");

async_test(t => {
  var image = new Image();
  // Notice that we don't set the image.crossOrigin property.
  image.src = "http://localhost:8000/security/resources/abe-allow-star.php";
  image.onload = function() {
    var offscreen = new OffscreenCanvas(10, 10);
    var ctx = offscreen.getContext('2d');
    ctx.drawImage(image, 0, 0);
    createImageBitmap(offscreen).then(imageBitmap => {
      var offscreen2 = new OffscreenCanvas(10, 10);
      var ctx2 = offscreen2.getContext('2d');
      ctx2.drawImage(imageBitmap, 0, 0);
      t.step(function() {
        verifyOffscreenCanvasTaintedThenDone(offscreen, t);
      });
    })
  }
}, "Verify that createImageBitmap(OffscreenCanvas) propagates the origin-clean flag.");





</script>