Add a minimal RtpTransport class for use by BaseChannel.

webrtc/pc/rtptransport.h

+/*
+ *  Copyright 2017 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.
+ */
+
+#ifndef WEBRTC_PC_RTPTRANSPORT_H_
+#define WEBRTC_PC_RTPTRANSPORT_H_
+
+namespace rtc {
+
+class PacketTransportInternal;
+
+}  // namespace rtc
+
+namespace webrtc {
+
+class RtpTransport {
+ public:
+  RtpTransport(const RtpTransport&) = delete;
+  RtpTransport& operator=(const RtpTransport&) = delete;
+
+  explicit RtpTransport(bool rtcp_mux_required)

[Taylor_Brandstetter, 2017/04/04 16:47:32]

I think it would make sense for the constructor to also take the initial set of
packet transports. Though this would require some shuffling of code (since the
initial transports are currently set in BaseChannel::SetTransports_n, called
from InitNetwork_n), so we can leave it as a TODO until it becomes more
straightforward.

+      : rtcp_mux_required_(rtcp_mux_required) {}
+
+  bool rtcp_mux_required() const { return rtcp_mux_required_; }
+
+  rtc::PacketTransportInternal* rtp_packet_transport() const {
+    return rtp_packet_transport_;
+  }
+  void set_rtp_packet_transport(rtc::PacketTransportInternal* rtp) {
+    rtp_packet_transport_ = rtp;
+  }
+
+  rtc::PacketTransportInternal* rtcp_packet_transport() const {
+    return rtcp_packet_transport_;
+  }
+  void set_rtcp_packet_transport(rtc::PacketTransportInternal* rtcp);
+
+ private:
+  // True if RTCP-multiplexing is required. rtcp_packet_transport_ should
+  // always be null in this case.
+  const bool rtcp_mux_required_;
+
+  // TODO(zstein): These should probably be owned here - they are currently
+  // owned by TransportController

[Taylor_Brandstetter, 2017/04/04 16:47:32]

I'm not so sure about this TODO. The current ownership model with the ORTC API
is that the application owns all created objects. We can talk about this more
later.

+  rtc::PacketTransportInternal* rtp_packet_transport_ = nullptr;
+  rtc::PacketTransportInternal* rtcp_packet_transport_ = nullptr;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_PC_RTPTRANSPORT_H_