Everything else in chromium works as before but I no longer have sound. Sound does work on Firefox in both YouTube and a personal web site with audio via mp3s on FreeBSD 11.0-RELEASE-p2
I've noticed this as well. It seems to work if I build with ALSA enabled.
As Ori mentioned, you now need to selected ALSA support for sound to work, at least in my case. I can only assume this is a change because I have been running chromium for years and don't recall having to do this in the past.
Fixed, would be updated, for now you can manually select "some" sound before building. It's my fault that it shipped without sound. I have OPTIONS_SET+= PULSEAUDIO in /etc/make.conf and I treated that the sound works for me as granted.