GdkPixbufAnimation that a pixbuf loader is currently creating.
In general it only makes sense to call this function after the "area_prepared"
signal has been emitted by the loader. If the loader doesn't have enough
bytes yet (hasn't emitted the "area_prepared" signal) this function will
return NULL.gdkPixbufLoaderGetAnimation(object)objectGdkPixbufLoader] A pixbuf loaderGdkPixbufAnimation] The GdkPixbufAnimation that the loader is loading, or NULL if
not enough data has been read to determine the information.