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

webrtc/video_engine/vie_channel_group.cc

Index: webrtc/video_engine/vie_channel_group.cc
diff --git a/webrtc/video_engine/vie_channel_group.cc b/webrtc/video_engine/vie_channel_group.cc
index ed4332ab08adc778581c142574912206b9a8140c..d6213789a480859fcea736b8e805ff2fbb2e6896 100644
--- a/webrtc/video_engine/vie_channel_group.cc
+++ b/webrtc/video_engine/vie_channel_group.cc
@@ -437,4 +437,11 @@ void ChannelGroup::OnNetworkChanged(uint32_t target_bitrate_bps,
       PacedSender::kDefaultPaceMultiplier * target_bitrate_bps / 1000,
       pad_up_to_bitrate_bps / 1000);
 }
+
+void ChannelGroup::OnSentPacket(const rtc::SentPacket& sent_packet) {
+  if (transport_feedback_adapter_.get() != nullptr) {
+    transport_feedback_adapter_->UpdateSendTime(sent_packet.packet_id,
+                                                sent_packet.send_time_ms);
+  }
+}
 }  // namespace webrtc