I want to be able to stay logged into Google/Facebook/Linkedin for convenience without other browser tabs knowing anything about it...or isomorphically, I want to be able to browse the internet while logged into those services without the pages I am browsing leaking data back to those sites. I'll take the hit of downloading 100k of jquery on my 20mbit pipe a few extra times.
I want my browser to sandbox my information to the same degree I can achieve by running separate browsers or setting up special browsing VM's.
I'm not sure what you mean. If this involves "sign in to Chromium" then that seems to involve signing in to Google, and that sort of defeats the purpose.
Incidentally, Chromium is what I use for Facebook...and only Facebook, on this particular computer. And signing into Chromium with my Google account seems to me to be a big information leak.
Chrome/chromium has the distinction of user profiles[1]. You can have separate windows have separate profiles (but not separate tabs). This has nothing to do with Google accounts. Each profile has their own 'jail' of chrome resources (cookies/history/tabs/etc). This is really useful when you need multiple persisting sessions while doing web dev or whatever else.
In the meantime I can recommend the RequestPolicy[1] add-on for Firefox. It's not exactly what you're asking for; it blocks cross-domain requests entirely instead. Since it uses a whitelist you'll have to add exceptions for the sites you use (images and stylesheets are often placed on a different domain). This takes a bit of time but I think it's worth it.
I want to be able to stay logged into Google/Facebook/Linkedin for convenience without other browser tabs knowing anything about it...or isomorphically, I want to be able to browse the internet while logged into those services without the pages I am browsing leaking data back to those sites. I'll take the hit of downloading 100k of jquery on my 20mbit pipe a few extra times.
I want my browser to sandbox my information to the same degree I can achieve by running separate browsers or setting up special browsing VM's.