Unregisters a GdkWindow from the widget that was previously set up with gtk_widget_register_window(). You need to call this when the window is no longer used by the widget, such as when you destroy it.
a GdkWindow Since 3.8
See Implementation
Unregisters a GdkWindow from the widget that was previously set up with gtk_widget_register_window(). You need to call this when the window is no longer used by the widget, such as when you destroy it.