This interface makes future refactoring difficult and is now in practice only implemented by PacketRouter. Bug: webrtc:10633 Change-Id: I3fcb8940781aa7431119649bde7594592a8c8851 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/141669 Reviewed-by: Björn Terelius <terelius@webrtc.org> Reviewed-by: Sebastian Jansson <srte@webrtc.org> Commit-Queue: Erik Språng <sprang@webrtc.org> Cr-Commit-Position: refs/heads/master@{#28251}