I've put a JSfiddle here so you can see code that is actually working...
Unfortunately this does not work on my local machine even though everything else does (I have other angular code running fine).
On my local machine I only see my html in the output if i use..
ng-bind-html-unsafe="message.content"
instead of...
ng-bind-html="message.content"
So, on JSfiddle it works when I leave the "unsafe" off, but on my local machine the unsafe has to be there, which seems undesirable from a security point of view.
I am loading the same version of Angular and sanitize, in the same order and my code I think is identical, only the environment seems to be different.
Any ideas?