Adding the ability to create an RtpSender without a track.

talk/app/webrtc/rtpsenderinterface.h

Index: talk/app/webrtc/rtpsenderinterface.h
diff --git a/talk/app/webrtc/rtpsenderinterface.h b/talk/app/webrtc/rtpsenderinterface.h
index fca98f21db5823397d789922bd21cc79b1d433b0..f54e8ca0905f3f9b2c652e73418e40f6bf2d46a3 100644
--- a/talk/app/webrtc/rtpsenderinterface.h
+++ b/talk/app/webrtc/rtpsenderinterface.h
@@ -35,6 +35,7 @@
 
 #include "talk/app/webrtc/proxy.h"
 #include "talk/app/webrtc/mediastreaminterface.h"
+#include "talk/session/media/mediasession.h"
 #include "webrtc/base/refcount.h"
 #include "webrtc/base/scoped_ref_ptr.h"
 
@@ -47,10 +48,24 @@ class RtpSenderInterface : public rtc::RefCountInterface {
   virtual bool SetTrack(MediaStreamTrackInterface* track) = 0;
   virtual rtc::scoped_refptr<MediaStreamTrackInterface> track() const = 0;
 
+  // Used to set the SSRC of the sender, once a local description has been set.
+  // If |ssrc| is 0, this indiates that the sender should disconnect from the
+  // underlying transport (this occurs if the sender isn't seen in a local
+  // description).
+  virtual void SetSsrc(uint32_t ssrc) = 0;
+  virtual uint32_t ssrc() const = 0;
+
+  // Audio or video sender?
+  virtual cricket::MediaType media_type() const = 0;
+
   // Not to be confused with "mid", this is a field we can temporarily use
   // to uniquely identify a receiver until we implement Unified Plan SDP.
   virtual std::string id() const = 0;
 
+  // TODO(deadbeef): Support one sender having multiple stream ids.
+  virtual void set_stream_id(const std::string& stream_id) = 0;
+  virtual std::string stream_id() const = 0;
+
   virtual void Stop() = 0;
 
  protected:
@@ -61,7 +76,12 @@ class RtpSenderInterface : public rtc::RefCountInterface {
 BEGIN_PROXY_MAP(RtpSender)
 PROXY_METHOD1(bool, SetTrack, MediaStreamTrackInterface*)
 PROXY_CONSTMETHOD0(rtc::scoped_refptr<MediaStreamTrackInterface>, track)
+PROXY_METHOD1(void, SetSsrc, uint32_t)
+PROXY_CONSTMETHOD0(uint32_t, ssrc)
+PROXY_CONSTMETHOD0(cricket::MediaType, media_type)
 PROXY_CONSTMETHOD0(std::string, id)
+PROXY_METHOD1(void, set_stream_id, const std::string&)
+PROXY_CONSTMETHOD0(std::string, stream_id)
 PROXY_METHOD0(void, Stop)
 END_PROXY()