Revert of Storing raw audio sink for default audio track.

talk/app/webrtc/webrtcsession.cc

Index: talk/app/webrtc/webrtcsession.cc
diff --git a/talk/app/webrtc/webrtcsession.cc b/talk/app/webrtc/webrtcsession.cc
index 17e4aaa86d41913624e702f7fe01b7302f8e391a..29a4f3394a32c8674d272aa7b007bc0053066c52 100644
--- a/talk/app/webrtc/webrtcsession.cc
+++ b/talk/app/webrtc/webrtcsession.cc
@@ -1320,14 +1320,13 @@
   }
 }
 
-void WebRtcSession::SetRawAudioSink(
-    uint32_t ssrc,
-    const rtc::scoped_refptr<AudioSinkInterface>& sink) {
+void WebRtcSession::SetRawAudioSink(uint32_t ssrc,
+                                    rtc::scoped_ptr<AudioSinkInterface> sink) {
   ASSERT(signaling_thread()->IsCurrent());
   if (!voice_channel_)
     return;
 
-  voice_channel_->SetRawAudioSink(ssrc, sink);
+  voice_channel_->SetRawAudioSink(ssrc, std::move(sink));
 }
 
 bool WebRtcSession::SetCaptureDevice(uint32_t ssrc,