SVGAnimateTransform does not support calcMode=discrete. I have a fix here, just unsure how to test. The animation testing API seems to be unstable for animateTransform. Sometimes the animation does not affect the transform of the target element.
Can't create a regression test, see bug 64104.
Created attachment 100017 [details]
Comment on attachment 100017 [details]
View in context: https://bugs.webkit.org/attachment.cgi?id=100017&action=review
Ok with some comments that you need to fix before landing.
> + Apply transform at 0% of animation if current percentage is smaller than 0.5 and at 100% if not.
Could be made more clear, you could start with Implement calcMode=discrete by... This sounds like a programmer speaking :) Try to incorporate the "This specifies that the animation function will jump from one value to the next without any interpolation." and why 0.5 was chosen.
> + Added a manual test. DRT crashes on an automated test with the SVG animation API. Opened a new bug report: 64104.
Could add the tracking bug for the animation framework problem.
> +<text x="10" y="20">Testing calcMode="discrete" for <animateTransform>. The rect should move without an interpoalted translation after 2s.</text>
interpoalted? Maybe reword a bit, maybe you can just use "jump" like in the spec definition.
Committed r90585: <http://trac.webkit.org/changeset/90585>