I was surprised to notice recently that my Toshiba Blu-Ray player has an early form of Google Chromecast in the Youtube player, I guess because I usually use Youtube on my Samsung, and I never tried the Search function on the Toshiba.
When you go to the Search function in the Youtube player, it offers to pair your Toshiba client with a remote web browser on another device, like a tablet or smartphone. It shows you a numeric ID code on the TV, and you go to youtube.com/pair
and enter the code to connect the Toshiba to Youtube in your web browser. The Toshiba then appears as a selectable video destination (by default "MyTV") in the Youtube settings. Then you can search for videos in your web browser and play them on the TV. The only control allowed is Pause and Play, and there's a second or two of lag, but it works. Sort of like Chromecast, but for Youtube only.