Chrome's security model doesn't normally allow any access to local devices/files from a "file://" URL. Adding "--allow-file-access-from-files" to the Chrome command line will let you get the offer and answer strings. Of course it still fails because Chrome doesn't support reliable data channels yet.
Thanks for the comment, @bscran. I don't get a PeerConnection even when running the source under "python -M SimpleHTTPServer 8080", even with unreliable data channels, so there's something about the ICE negotiation that needs to be fixed up before we get to these other problems.