From May 7th, 2017 to May 7th, 2017, 100% user give 5-star rating. for Youtube Player Maximizer 网页全屏 chrome extension.
Works 100% is exactly what I was looking for. Thanks! Only issue is that I can't figure out how to go back to before running the extension. So the tab is basically "locked in" as a full screen of the video. Cannot reduce it to add comments etc..