Function cogl_sys::cogl_onscreen_add_dirty_callback

pub unsafe extern "C" fn cogl_onscreen_add_dirty_callback(
    onscreen: *mut CoglOnscreen, 
    callback: CoglOnscreenDirtyCallback, 
    user_data: *mut c_void, 
    destroy: CoglUserDataDestroyCallback
) -> *mut CoglOnscreenDirtyClosure