I've done it. Finally finished. It took me a whole day and most the night, and the better part of the next morning, but I can finally say I've finished one of the things I've been longing for -- the ability to watch Youtube videos in the Rift!
I've implemented it as a Chrome extension, and there are many things that can be improved:
I will followup with a more detailed technical breakdown of the hacks required to get this working.