Move ready to send logic from BaseChannel to RtpTransport.

webrtc/pc/rtptransport.h

Index: webrtc/pc/rtptransport.h
diff --git a/webrtc/pc/rtptransport.h b/webrtc/pc/rtptransport.h
index f5ffe3fe5f154aad0956d81a1877358f50ad6e48..f9bee1b6cc7da03d6ad5a93680b0a70f004bf8cd 100644
--- a/webrtc/pc/rtptransport.h
+++ b/webrtc/pc/rtptransport.h
@@ -12,34 +12,38 @@
 #define WEBRTC_PC_RTPTRANSPORT_H_
 
 #include "webrtc/api/ortc/rtptransportinterface.h"
+#include "webrtc/base/sigslot.h"
 
 namespace rtc {
 
+class CopyOnWriteBuffer;
+struct PacketOptions;
 class PacketTransportInternal;
 
 }  // namespace rtc
 
 namespace webrtc {
 
-class RtpTransport : public RtpTransportInterface {
+class RtpTransport : public RtpTransportInterface, public sigslot::has_slots<> {
  public:
   RtpTransport(const RtpTransport&) = delete;
   RtpTransport& operator=(const RtpTransport&) = delete;
 
-  explicit RtpTransport(bool rtcp_mux_required)
-      : rtcp_mux_required_(rtcp_mux_required) {}
+  explicit RtpTransport(bool rtcp_mux_enabled)
+      : rtcp_mux_enabled_(rtcp_mux_enabled) {}
 
-  bool rtcp_mux_required() const { return rtcp_mux_required_; }
+  bool rtcp_mux_enabled() const { return rtcp_mux_enabled_; }
+  void SetRtcpMuxEnabled(bool enable);
 
   rtc::PacketTransportInternal* rtp_packet_transport() const {
     return rtp_packet_transport_;
   }
-  void set_rtp_packet_transport(rtc::PacketTransportInternal* rtp);
+  void SetRtpPacketTransport(rtc::PacketTransportInternal* rtp);
 
   rtc::PacketTransportInternal* rtcp_packet_transport() const {
     return rtcp_packet_transport_;
   }
-  void set_rtcp_packet_transport(rtc::PacketTransportInternal* rtcp);
+  void SetRtcpPacketTransport(rtc::PacketTransportInternal* rtcp);
 
   PacketTransportInterface* GetRtpPacketTransport() const override;
   PacketTransportInterface* GetRtcpPacketTransport() const override;
@@ -48,18 +52,40 @@ class RtpTransport : public RtpTransportInterface {
   RTCError SetRtcpParameters(const RtcpParameters& parameters) override;
   RtcpParameters GetRtcpParameters() const override;
 
+  // Called whenever a transport's ready-to-send state changes. The argument
+  // is true if all used transports are ready to send. This is more specific
+  // than just "writable"; it means the last send didn't return ENOTCONN.
+  sigslot::signal1<bool> SignalReadyToSend;
+
+  bool IsWritable(bool rtcp) const;
+
+  bool SendPacket(bool rtcp,
+                  const rtc::CopyOnWriteBuffer* packet,
+                  const rtc::PacketOptions& options,
+                  int flags);
+
  protected:
   // TODO(zstein): Remove this when we remove RtpTransportAdapter.
   RtpTransportAdapter* GetInternal() override;
 
  private:
-  // True if RTCP-multiplexing is required. rtcp_packet_transport_ should
-  // always be null in this case.
-  const bool rtcp_mux_required_;
+  void OnReadyToSend(rtc::PacketTransportInternal* transport);
+
+  // Updates "ready to send" for an individual channel and fires
+  // SignalReadyToSend.
+  void SetReadyToSend(bool rtcp, bool ready);
+
+  void MaybeSignalReadyToSend();
+
+  bool rtcp_mux_enabled_;
 
   rtc::PacketTransportInternal* rtp_packet_transport_ = nullptr;
   rtc::PacketTransportInternal* rtcp_packet_transport_ = nullptr;
 
+  bool ready_to_send_ = false;
+  bool rtp_ready_to_send_ = false;
+  bool rtcp_ready_to_send_ = false;
+
   RtcpParameters rtcp_parameters_;
 };