Comment 4 for bug 1608418

While it is great to see that shaped windows are now decorated with a drop shadow, this patch makes window switching very slow when a shaped window is rendered. This is very noticeable when using for example crossover office. Switching to a crossover office application window takes about 2 seconds and the rendering of the dropshadow is delayed by another two seconds. I'm using a hidpi display so it's possible that the effect is less prominent on lower-resolution displays.