Normally I display Youtube as shown in this other Answer (but that loads a Flash Player version, which you may not want). PS: Remember it's use .com/v/VID_ID
for Flash Player or use .com/embed/VID_ID
for HTML5 Player.
Any ideas how to play the video so even if the source is larger I can
resize it to the viewport size?.
You say you have similar code as the Android example posted as Answer? Why not try to open an iframe
instead since that would allow a resize option?
An example of a custom size Youtube iframe...
<iframe width="800" height="600" src="https://www.youtube.com/embed/"+ VID +"?autoplay=1" frameborder="0" allowfullscreen></iframe>
To open within iframe you'd have to make a dynamic webpage by code. Code below is untested but is based on this idea from Adobe forums. Just a starting point you could adjust / fix...
var html_Dynamic : String;
html_Dynamic = "<!DOCTYPE HTML>" +
"<html>" +
"<body>" +
"<iframe class=\"youtube-player\" style=\"border: 0; width: 100%; height: 100%; padding:0px; margin:0px\" id=\"ytplayer\" type=\"text/html\" src=\"https://www.youtube.com/embed/" +
VID + "?fs=0\" frameborder=\"0\">\n" + "</iframe>\n";
"</body>" +
"</html>";