Add QuicTransportChannel methods for QUIC streams

webrtc/p2p/quic/quicsession.cc

Index: webrtc/p2p/quic/quicsession.cc
diff --git a/webrtc/p2p/quic/quicsession.cc b/webrtc/p2p/quic/quicsession.cc
index 281af5e3a745a254475f5c85b8d63949c8452384..a70aa0b01d2e1a62986807855c32daaf047cfb70 100644
--- a/webrtc/p2p/quic/quicsession.cc
+++ b/webrtc/p2p/quic/quicsession.cc
@@ -75,7 +75,7 @@ ReliableQuicStream* QuicSession::CreateOutgoingDynamicStream(
     net::SpdyPriority priority) {
   ReliableQuicStream* stream = CreateDataStream(GetNextOutgoingStreamId());
   if (stream) {
-    ActivateStream(stream);
+    ActivateStream(stream);  // QuicSession owns the stream.
   }
   return stream;
 }