Vita had a screenshot sharing function too and I think the wiiu may also have had one.I never used it. I see there's a Brag Clip button. Was there a way to share that outside of OnLive? Obviously Sony was inspired by it and expanded upon it seeing that they bought their patents. There could be a distinct difference there, but if not then I suppose it has been around since OnLive in some form or fashion.
Edit: Looks like you could upload this to Facebook.
No dedicated button on vita though you had to press two together.