Chrome Canary is the only Chrome version that has working SCTP (reliable) datachannel support at the moment. It's broken(undetectable also) in every version before that (you can try, the website won't stop any version, just display warnings).

I did have unreliable datachannel support initially, but as both Firefox & Chrome now support reliable, I see no reason to keep that overhead/extra code around. Hopefully working reliable datachannels in Chrome will reach the primary version soon!