Perspective with a CSS 3D transform in SVG is rendered incorrectly. See example here: http://tachatte.org/css-transform-svg/square.svg The way WebKit renders it is stretching, not perspective. I believe the correct way to render this document can be observed using Firefox.
Thank you for taking the time to file this. The root issue is we don't currently support composited layers in SVG. Unfortunately this is difficult to fix :( *** This bug has been marked as a duplicate of bug 23113 ***