Bugzilla – Bug 15841
animation-fill-mode:fractional iteration counts, new animation-direction values and step()
Last modified: 2014-10-20 22:03:16 UTC
FWIW webkit just landed support for fractional iterations, but keeps the fill mode as the 0 or 100 keyframe (which I think is not what people would expect)
New thread on the topic summarizing a number of issues. I suspect this property may need to be extensively rewritten to account for these issues, as well as 15840 and 16410.
This has since been addressed by dbaron's edits.