ScreenAndUserClipping
ScreenAndUserClipping(windowContentClipping));
= &ScreenAndUserClipping(&windowContentClipping);
BRegion& ScreenAndUserClipping(
region.IntersectWith(&view->ScreenAndUserClipping(&fContentRegion));
&view->ScreenAndUserClipping(&fContentRegion));
BRegion redraw(ScreenAndUserClipping(windowContentClipping));