i create a frame like this:
var f = document.createElement('iframe');
f.src = 'https://apis.google.com/u/0/wm/4/_/widget/render/comments?usegapi=1&first_party_property=YOUTUBE&href=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D' + location.href.match(/v=(.+?)([#&]|$)/)[1];
but I would want the frame to have the same height the source has, so all is visible, instead of setting a static height and getting scrollbars.
maybe I did it wrong, but overflow = visible
didn't seem to work.