The latest version of the CSS Animation and CSS Transition specs give rules for how to handle animation between transform lists. Basically, if the lists match in size and the corresponding operators in the list match, animation is done on an operation-by-operation basis. Otherwise, the lists are reduced to and AffineTransform and those are animated as described in https://bugs.webkit.org/show_bug.cgi?id=20667.
Created attachment 23327 [details] Patch, including LayoutTest files
Comment on attachment 23327 [details] Patch, including LayoutTest files r=me
Created attachment 23382 [details] Replacement patch - now against changelist 36358
Committed r36362 M WebCore/rendering/RenderLayer.cpp M WebCore/rendering/style/RenderStyle.cpp M WebCore/rendering/style/RenderStyle.h M WebCore/ChangeLog M WebCore/css/CSSStyleSelector.cpp M WebCore/css/CSSStyleSelector.h M WebCore/page/animation/AnimationBase.h M WebCore/page/animation/ImplicitAnimation.h M WebCore/page/animation/KeyframeAnimation.cpp M WebCore/page/animation/KeyframeAnimation.h M WebCore/page/animation/AnimationBase.cpp M WebCore/page/animation/ImplicitAnimation.cpp M LayoutTests/ChangeLog
Committed r36468 M LayoutTests/ChangeLog A LayoutTests/transitions/transform-op-list-match.html A LayoutTests/transitions/transform-op-list-no-match-expected.txt A LayoutTests/transitions/transform-op-list-match-expected.txt A LayoutTests/transitions/transform-op-list-no-match.html