Repetitions are currently handled by adjusting percentage (percentage += repeatCount). This doesn't work for <animateTransform> as each repetition has to be post-multiplied to the animated transform list. By-animations are equal to values="0;by" animations in SMIL. 0 is the neutral element of addition, which is the _zero_ matrix, not the identity matrix for SVGTransform. See moz guys discussing the same problem, with the same outcome: http://brian.sol1.net/svg/animatetransform-issues/by-animation-and-scale-transformations/
Created attachment 139171 [details] Patch
Comment on attachment 139171 [details] Patch Attachment 139171 [details] did not pass qt-wk2-ews (qt): Output: http://queues.webkit.org/results/12557170
Comment on attachment 139171 [details] Patch Attachment 139171 [details] did not pass qt-ews (qt): Output: http://queues.webkit.org/results/12556176
Comment on attachment 139171 [details] Patch Attachment 139171 [details] did not pass mac-ews (mac): Output: http://queues.webkit.org/results/12551178
Uploading patch v2, which will fix the release builds.
Created attachment 139192 [details] Patch v2
Comment on attachment 139192 [details] Patch v2 r=me
Committed r115425: <http://trac.webkit.org/changeset/115425>