Connect TurnPort and TCPPort to AsyncPacketSocket::SignalSentPacket.

webrtc/p2p/base/port.h

Index: webrtc/p2p/base/port.h
diff --git a/webrtc/p2p/base/port.h b/webrtc/p2p/base/port.h
index 57608b5b14deefb57277e9fa044c6d9ca9f1fbfb..d9f15a43584487c8bbac21c1411e9fe2fd82495e 100644
--- a/webrtc/p2p/base/port.h
+++ b/webrtc/p2p/base/port.h
@@ -280,7 +280,11 @@ class Port : public PortInterface, public rtc::MessageHandler,
                             const std::string& remote_ufrag);
 
   // Called when a packet has been sent to the socket.
-  void OnSentPacket(const rtc::SentPacket& sent_packet);
+  // This is made pure virtual to notify the one implementing new Ports that
+  // OnSentPacket MUST be connected to the socket and passed on to
+  // PortInterface.

[pthatcher1, 2016/01/13 19:42:36]

I think this needs to be more explicit about what should connect to what. 
Perhaps:

This is made pure virtual to notify subclasses of Port that they MUST listen to
AsyncPacketSocket::SignalSentPacket and then call PortInterface::OnSentPacket.

[stefan-webrtc, 2016/01/14 10:14:38]

Agree, your text is better. Thanks!

+  virtual void OnSentPacket(rtc::AsyncPacketSocket* socket,
+                            const rtc::SentPacket& sent_packet) = 0;
 
   // Called when the socket is currently able to send.
   void OnReadyToSend();