1. clip-path: polygon(...) is not supported by FireFox. It supports only URL value. https://developer.mozilla.org/en-US/docs/Web/CSS/clip-path. 2. CanvasRenderingContext2D.ellipse() is not supported by FireFox. https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/ellipse. 3. CanvasRenderingContext2D.drawImage() draws an SVG image only when it has an intrinsic size. https://bugzilla.mozilla.org/show_bug.cgi?id=700533. A test page is http://phrogz.net/SVG/svg_to_png.xhtml.
Created attachment 266490 [details] Patch
This bug is not relevant anymore. MotionMark sub tests had changed long time ago and and all of them work as expected on FireFox.