redraw() has some major problem, visible under X; one, it was never actually calling the XSync that was there, because the #define is MOZ_ENABLE_GTK2 and not MOZ_WIDGET_GTK2. Two, calling XSync after each invalidate isn't quite right; usually you want to test a number of calls all at once and then XSync afterwards or you don't get a reasonable impression of performance. I fixed the first, and I took the opportunity to change how redraw works -- it now has an optional argument that lets you specify the number of sync invalidates to do, and it returns the number of ms the entire cycle took.

improvements as mentioned above.