Revert of Storing raw audio sink for default audio track.

talk/app/webrtc/remoteaudiosource.cc

Index: talk/app/webrtc/remoteaudiosource.cc
diff --git a/talk/app/webrtc/remoteaudiosource.cc b/talk/app/webrtc/remoteaudiosource.cc
index 45e2e9ec8af610ed4f40e2e4ffe1b3405641c7d0..e904dd91925e48654832a5bb769f2e971c8b513e 100644
--- a/talk/app/webrtc/remoteaudiosource.cc
+++ b/talk/app/webrtc/remoteaudiosource.cc
@@ -96,7 +96,8 @@
   // To make sure we always get notified when the provider goes out of scope,
   // we register for callbacks here and not on demand in AddSink.
   if (provider) {  // May be null in tests.
-    provider->SetRawAudioSink(ssrc, new rtc::RefCountedObject<Sink>(this));
+    provider->SetRawAudioSink(
+        ssrc, rtc::scoped_ptr<AudioSinkInterface>(new Sink(this)));
   }
 }