Delete default_send_ssrc_.

webrtc/media/engine/webrtcvideoengine2.cc

Index: webrtc/media/engine/webrtcvideoengine2.cc
diff --git a/webrtc/media/engine/webrtcvideoengine2.cc b/webrtc/media/engine/webrtcvideoengine2.cc
index e34056d905257371b6f9c0db015f38a3bdcf3a85..a45477ce1197ea029e464e61f4d46cbcf76dd866 100644
--- a/webrtc/media/engine/webrtcvideoengine2.cc
+++ b/webrtc/media/engine/webrtcvideoengine2.cc
@@ -619,7 +619,6 @@ WebRtcVideoChannel2::WebRtcVideoChannel2(
 
   rtcp_receiver_report_ssrc_ = kDefaultRtcpReceiverReportSsrc;
   sending_ = false;
-  default_send_ssrc_ = 0;
   RTC_DCHECK(ValidateCodecFormats(recv_codecs));
   recv_codecs_ = FilterSupportedCodecs(MapCodecs(recv_codecs));
 }
@@ -1030,9 +1029,6 @@ bool WebRtcVideoChannel2::AddSendStream(const StreamParams& sp) {
     for (auto& kv : receive_streams_)
       kv.second->SetLocalSsrc(ssrc);
   }
-  if (default_send_ssrc_ == 0) {
-    default_send_ssrc_ = ssrc;
-  }
   if (sending_) {
     stream->Start();
   }
@@ -1043,15 +1039,9 @@ bool WebRtcVideoChannel2::AddSendStream(const StreamParams& sp) {
 bool WebRtcVideoChannel2::RemoveSendStream(uint32_t ssrc) {
   LOG(LS_INFO) << "RemoveSendStream: " << ssrc;
 
-  if (ssrc == 0) {
-    if (default_send_ssrc_ == 0) {
-      LOG(LS_ERROR) << "No default send stream active.";
-      return false;
-    }
-
-    LOG(LS_VERBOSE) << "Removing default stream: " << default_send_ssrc_;
-    ssrc = default_send_ssrc_;
-  }
+  // TODO(nisse): ssrc == 0 is technically valid, but currently not
+  // supported.
+  RTC_DCHECK(ssrc != 0);

[pbos-webrtc, 2016/03/21 09:54:04]

I think this should return false and not crash, because I think we can add these
from munged SDP.

[nisse-webrtc, 2016/03/21 14:23:06]

Does that apply to AddSendStream too?

[pthatcher1, 2016/03/22 21:30:28]

RemoveSendStream will only have passed to it the SSRC that was passed into
AddSendStream.  And, yes, the SDP can have SSRC=0:

https://code.google.com/p/chromium/codesearch#chromium/src/third_party/webrtc...

I'm guessing that we blow up in many places if that happens, but there's really
no reason that we should.  So we ought to be moving in the direction of removing
those blow ups, not adding them.

 
   WebRtcVideoSendStream* removed_stream;
   {
@@ -1084,10 +1074,6 @@ bool WebRtcVideoChannel2::RemoveSendStream(uint32_t ssrc) {
 
   delete removed_stream;
 
-  if (ssrc == default_send_ssrc_) {
-    default_send_ssrc_ = 0;
-  }
-
   return true;
 }