chromium/third_party/blink/web_tests/http/tests/mediasession/set-null-metadata.html

<!DOCTYPE html>
<title>MediaSession Mojo Test</title>
<script src="../../../resources/testharness.js"></script>
<script src="../../../resources/testharnessreport.js"></script>
<script type="module">
import {MediaSessionServiceMock} from './resources/mediasessionservice-mock.js';

async_test(function(t) {
  const m = new MediaSessionServiceMock();
  m.setMetadataCallback(t.step_func(function(receivedMetadata) {
    assert_equals(receivedMetadata, null);
    t.done();
  }));
  window.navigator.mediaSession.metadata = null;
}, "test that null MediaMetadata is correctly propagated");

</script>