feature-policy-web-share-use-count.html

<!DOCTYPE html>
<title>Feature-Policy web-share</title>
<div>web-share</div>
<script>

const WebSharePolicyAllow = 3368; // From web_feature.mojom
const WebSharePolicyDisallow = 3369; // From web_feature.mojom

document.addEventListener('keypress', function() {
  internals.clearUseCounter(document, WebSharePolicyAllow);
  internals.clearUseCounter(document, WebSharePolicyDisallow);

  navigator.share({}).catch(error => {
    if (internals.isUseCounted(document, WebSharePolicyAllow))
      parent.postMessage({ type: 'result', enabled: true }, '*');
    else if (internals.isUseCounted(document, WebSharePolicyDisallow))
      parent.postMessage({ type: 'result', enabled: false }, '*');
  });
});

window.onload = function() {
  focus();
  eventSender.keyDown('a', []);
}
</script>

chromium/third_party/blink/web_tests/http/tests/feature-policy/resources/feature-policy-web-share-use-count.html