Modify PeerConnection for end-to-end QuicDataChannel usage

webrtc/api/peerconnection.cc

Index: webrtc/api/peerconnection.cc
diff --git a/webrtc/api/peerconnection.cc b/webrtc/api/peerconnection.cc
index b2b8062ca843a00015851e2f9a735d53e13fee0f..baa2376f31e13a2a7af51ead7394cfbc76bbc9fa 100644
--- a/webrtc/api/peerconnection.cc
+++ b/webrtc/api/peerconnection.cc
@@ -833,6 +833,25 @@ PeerConnection::CreateDataChannel(
     const std::string& label,
     const DataChannelInit* config) {
   TRACE_EVENT0("webrtc", "PeerConnection::CreateDataChannel");
+#ifdef USE_QUIC
+  // TODO(mikescarlett): Handle case when CreateDataChannel() is called
+  // before QUIC is specified in the session description.

[Taylor Brandstetter, 2016/04/01 23:23:41]

Can't "use quic" be a parameter in RTCConfiguration, at the PeerConnection
initialization time? Or maybe it could be a parameter in the DataChannelInit.

[mikescarlett, 2016/04/05 19:58:49]

This seems necessary since QUIC won't be negotiated.

+  if (session_->data_channel_type() == cricket::DCT_QUIC) {
+    cricket::QuicTransportChannel* quic_transport_channel =
+        session_->quic_transport_channel();
+    RTC_DCHECK(quic_transport_channel != nullptr);

[Taylor Brandstetter, 2016/04/01 23:23:41]

It should be possible to create a data channel even if the underlying QUIC
transport channel doesn't exist.

[mikescarlett, 2016/04/05 19:58:48]

Fixed.

+    rtc::scoped_refptr<QuicDataChannel> channel(new QuicDataChannel(
+        quic_transport_channel, session_->signaling_thread(),
+        session_->worker_thread(), label, config));
+    quic_data_channels_.push_back(channel);
+    if (!quic_transport_) {
+      quic_transport_.reset(new QuicTransport(quic_transport_channel));
+    }

[pthatcher1, 2016/03/30 20:34:47]

It seems like this should logically go a few lines up, just before "new
QuicDataChannel".

+    quic_transport_->RegisterDataChannel(channel);
+    return channel;
+  }
+#endif  // USE_QUIC
+
   bool first_datachannel = !HasDataChannels();
 
   rtc::scoped_ptr<InternalDataChannelInit> internal_config;