Yeah, for the rapid release mobile browsers I'm just tracking the latest version due to the difficulties involved in going back to test older versions. So indeed that data is essentially lost here, but since for most features the introduction version matches that of the desktop version.

Additionally [see here](https://twitter.com/jwatte/statuses/414101354223652864) for the reason I downgraded the support to "partial".  So I think I'll just close this PR and manually remove the part of the note that no longer applies.