web-audio.html | Explore in Territory

<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/common/utils.js"></script>
<script src="/speculation-rules/prerender/resources/utils.js"></script>
<script>

  const params = new URLSearchParams(location.search);

  // The main test page (restriction-web-audio.html) loads this page without
  // `prerendering` parameter.
  const isPrerendering = params.has('prerendering');

  if (!isPrerendering) {
    // If this page loads without `prerendering` parameter, it calls
    // loadInitiatorPage() to prerender itself with the `prerendering`
    // parameter.
    // This initiator page waits for the `readyToActivate` message from the
    // main test page, and navigates to the prerendered page to activate it.
    loadInitiatorPage();
  } else {
    // The page loads with `prerendering` parameter.
    const channel = new PrerenderChannel('result-channel');

    // Set AutoplayPolicy to permit AudioContext to run without user gesture.
    // This is the special case we want to verify in this test.
    // If this isn't set, AudioContext will be just suspended as a user gesture
    // should not be given while prerendering, and it just works as usual ways.
    internals.settings.setAutoplayPolicy('no-user-gesture-required');

    // Construct AudioContext. It should be in the suspended state while
    // prerendering.
    const audioContext = new AudioContext();

    // Call resume() to register a resume promise. Once the page is activated,
    // the AudioContext is automatically resumed and the resume promises will be
    // resolved. So, following message expsts `prerendering` to be false, and
    // `audiocontext` to be `running`.
    audioContext.resume().then(() => {
      channel.postMessage({
        event: 'resume',
        prerendering: document.prerendering,
        audiocontext: audioContext.state
      });
      channel.close();
    });

    // Report the initial state. The message expects `prerendering` to be true,
    // and `audiocontext` to be `suspended`. This message also notifies the test
    // page to send a message to initiator page to activate.
    channel.postMessage({
      event: 'start',
      prerendering: document.prerendering,
      audiocontext: audioContext.state
    });
  }

</script>
chromium/third_party/blink/web_tests/wpt_internal/prerender/resources/web-audio.html
