With some of the more advanced things like NaCl, it wouldn't surprise me at all if some of the functionality looked the same, or even had quite a similar purpose.

We don't know if the malware signature is on bits that do bad things, or just bits that had been unique to Zeus until now.

Edit: Also, some people are reporting no problems. It could be that those Chrome instances really were infected. We don't know where they got the download for Chrome from.