Remove manual discardWindowPixmap() calls in InternalClient
SurfaceItemInternal will discard the current pixmap if the buffer size changes. Also, one of the goal of the scene redesign is to keep things such as this out of Toplevel subclasses.
SurfaceItemInternal will discard the current pixmap if the buffer size changes. Also, one of the goal of the scene redesign is to keep things such as this out of Toplevel subclasses.