@aestes, @danyao, @rsolomakhin, moving discussion from #885.

HTML has a new activation model. Right now, we presumedly have "transient" activation for show():

window.onclick = () => {
   // set up payment stuff...
   const pay = request.show();
   // Does this succeed or reject? i.e., did .show() "consume" the user activation.
   document.body.requestFullscreen();
}

Presumedly, because of the modal nature of .show() we want to "consume" the activation, so that things like requestFullscreen() would fail if called immediately after .show().