Wire up transport sequence number / send time callbacks to webrtc via libjingle.

webrtc/base/asynctcpsocket.cc

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 250 matching lines @@
   AppendToOutBuffer(&pkt_len, kPacketLenSize);
   AppendToOutBuffer(pv, cb);
 
   int res = FlushOutBuffer();
   if (res <= 0) {
     // drop packet if we made no progress
     ClearOutBuffer();
     return res;
   }
 
+  rtc::SentPacket sent_packet(options.packet_id, rtc::Time());
+  SignalPacketSent(this, GetRemoteAddress(), sent_packet);

[pthatcher1, 2015/10/05 18:30:14]

We have SignalPacketSent, but that doesn't signal when the packet gets dropped
above and is never sent.  Should we have a SignalPacketDropped or a field on
sent_packet that's ".dropped" (of course, then SentPacket would be a misnomer,
and we'd have to think of a different name)?  In other words, would webrtc::Call
want to know that we dropped a packet before it went out?

[stefan-webrtc, 2015/10/06 13:00:19]

This is not something I'm trying to achieve right now, but could potentially be
something we want to do in the future. I'd suggest that we make those changes
when/if we need them.

We could already infer that by identifying that a certain packet id didn't get a
SignalPacketSent().

[pthatcher1, 2015/10/06 20:23:55]

Makes sense.

+
   // We claim to have sent the whole thing, even if we only sent partial
   return static_cast<int>(cb);
 }
 
 void AsyncTCPSocket::ProcessInput(char * data, size_t* len) {
   SocketAddress remote_addr(GetRemoteAddress());
 
   while (true) {
     if (*len < kPacketLenSize)
       return;
@@ skipping 10 matching lines @@
       memmove(data, data + kPacketLenSize + pkt_len, *len);
     }
   }
 }
 
 void AsyncTCPSocket::HandleIncomingConnection(AsyncSocket* socket) {
   SignalNewConnection(this, new AsyncTCPSocket(socket, false));
 }
 
 }  // namespace rtc