5 years? Don't see any chance for extinction.

There are tons of non-HTTPS websites out there. A myriad of forsaken ones that are still running because no one had remembered to do anything to them, and a myriad of ones whose sysadmins just don't care about TLS at all.

A non-obtrusive "insecure connection" warning is probably going to happen quite soon, but I just don't see any chance of mass HTTPS migration besides the high-profile sites, newborn sites and geeks that would stand for the cause.

Otherwise, a pretty large fraction of the WWW is going to be lost.

I'm guessing in 10 years Chrome will refuse to connect to http hosts, given Google's track record of aggressively unilaterally deprecating and disabling web features they consider harmful.