Data has been handled in the probe and will not be forwarded further.
For events and buffers this is the same behaviour as gst_pad_probe_drop (except that in this case you
need to unref the buffer or event yourself). For queries it will also return true to the caller. The
probe can also modify the FlowReturn value by using the
GST_PAD_PROBE_INFO_FLOW_RETURN() accessor. Note that the resulting query must contain valid entries. Since: 1.6