Introduce rtc::PacketTransportInterface and let cricket::TransportChannel inherit.

webrtc/pc/channel.cc

Index: webrtc/pc/channel.cc
diff --git a/webrtc/pc/channel.cc b/webrtc/pc/channel.cc
index f22bdc4ca41029155f2fe4fe511bb9c2765ee679..2f9447d3ce15a5ce907befd154fabd1e328a1534 100644
--- a/webrtc/pc/channel.cc
+++ b/webrtc/pc/channel.cc
@@ -24,6 +24,7 @@
 #include "webrtc/base/trace_event.h"
 #include "webrtc/media/base/mediaconstants.h"
 #include "webrtc/media/base/rtputils.h"
+#include "webrtc/p2p/base/packettransport.h"
 #include "webrtc/p2p/base/transportchannel.h"
 #include "webrtc/pc/channelmanager.h"
 
@@ -527,17 +528,20 @@ bool BaseChannel::SetCryptoOptions(const rtc::CryptoOptions& crypto_options) {
   return true;
 }
 
-void BaseChannel::OnWritableState(TransportChannel* channel) {
+void BaseChannel::OnWritableState(rtc::PacketTransport* pt) {
+  TransportChannel* channel = static_cast<TransportChannel*>(pt);
   RTC_DCHECK(channel == transport_channel_ ||
              channel == rtcp_transport_channel_);
   RTC_DCHECK(network_thread_->IsCurrent());
   UpdateWritableState_n();
 }
 
-void BaseChannel::OnChannelRead(TransportChannel* channel,
-                                const char* data, size_t len,
+void BaseChannel::OnChannelRead(rtc::PacketTransport* pt,
+                                const char* data,
+                                size_t len,
                                 const rtc::PacketTime& packet_time,
                                 int flags) {
+  TransportChannel* channel = static_cast<TransportChannel*>(pt);
   TRACE_EVENT0("webrtc", "BaseChannel::OnChannelRead");
   // OnChannelRead gets called from P2PSocket; now pass data to MediaEngine
   RTC_DCHECK(network_thread_->IsCurrent());
@@ -549,7 +553,8 @@ void BaseChannel::OnChannelRead(TransportChannel* channel,
   HandlePacket(rtcp, &packet, packet_time);
 }
 
-void BaseChannel::OnReadyToSend(TransportChannel* channel) {
+void BaseChannel::OnReadyToSend(rtc::PacketTransport* pt) {
+  TransportChannel* channel = static_cast<TransportChannel*>(pt);
   RTC_DCHECK(channel == transport_channel_ ||
              channel == rtcp_transport_channel_);
   SetTransportChannelReadyToSend(channel == rtcp_transport_channel_, true);
@@ -1445,7 +1450,7 @@ void BaseChannel::FlushRtcpMessages_n() {
   }
 }
 
-void BaseChannel::SignalSentPacket_n(TransportChannel* /* channel */,
+void BaseChannel::SignalSentPacket_n(rtc::PacketTransport* /* pt */,
                                      const rtc::SentPacket& sent_packet) {
   RTC_DCHECK(network_thread_->IsCurrent());
   invoker_.AsyncInvoke<void>(
@@ -1641,12 +1646,13 @@ void VoiceChannel::GetActiveStreams_w(AudioInfo::StreamList* actives) {
   media_channel()->GetActiveStreams(actives);
 }
 
-void VoiceChannel::OnChannelRead(TransportChannel* channel,
-                                 const char* data, size_t len,
+void VoiceChannel::OnChannelRead(rtc::PacketTransport* pt,
+                                 const char* data,
+                                 size_t len,
                                  const rtc::PacketTime& packet_time,
-                                int flags) {
-  BaseChannel::OnChannelRead(channel, data, len, packet_time, flags);
-
+                                 int flags) {
+  BaseChannel::OnChannelRead(pt, data, len, packet_time, flags);
+  TransportChannel* channel = static_cast<TransportChannel*>(pt);
   // Set a flag when we've received an RTP packet. If we're waiting for early
   // media, this will disable the timeout.
   if (!received_media_ && !PacketIsRtcp(channel, data, len)) {