Google Code also had hg support before it had git support, if I remember right. Certainly the SVN -> hg migration was easier than SVN -> git if you were using it.
And canonical's launchpad.net
At the time I’m talking about that was a proprietary forge for bzr, Canonical’s unnecessary version of baz, which was the community fork of tla, which was the GNU experiment in DVCS with an even worse interface than git.
And at that point, even the use of dvcs was in question, so you could use svn on google's forge, or sourceforge. Launchpad had bzr support too.
It wasn't clear github was going to win until it was clear that git was going to win.