Support for remote audio into tracks

talk/app/webrtc/remoteaudiotrack.cc

Index: talk/app/webrtc/remoteaudiotrack.cc
diff --git a/talk/app/webrtc/remoteaudiotrack.cc b/talk/app/webrtc/remoteaudiotrack.cc
index df27f05e4859b2f423a950485aef50915501dd41..8d0306f34697dc64f866c03eaee58438ed271fab 100644
--- a/talk/app/webrtc/remoteaudiotrack.cc
+++ b/talk/app/webrtc/remoteaudiotrack.cc
@@ -26,3 +26,69 @@
  */
 
 #include "talk/app/webrtc/remoteaudiotrack.h"
+
+#include "talk/app/webrtc/remoteaudiosource.h"
+
+using rtc::scoped_refptr;
+
+namespace webrtc {
+
+// static
+scoped_refptr<RemoteAudioTrack> RemoteAudioTrack::Create(
+    const std::string& id,
+    const scoped_refptr<RemoteAudioSource>& source) {
+  return new rtc::RefCountedObject<RemoteAudioTrack>(id, source);
+}
+
+RemoteAudioTrack::RemoteAudioTrack(
+    const std::string& label,
+    const scoped_refptr<RemoteAudioSource>& source)
+    : MediaStreamTrack<AudioTrackInterface>(label), audio_source_(source) {
+  audio_source_->RegisterObserver(this);
+  TrackState new_state = kInitializing;
+  switch (audio_source_->state()) {
+    case MediaSourceInterface::kLive:
+    case MediaSourceInterface::kMuted:
+      new_state = kLive;
+      break;
+    case MediaSourceInterface::kEnded:
+      new_state = kEnded;
+      break;
+    case MediaSourceInterface::kInitializing:
+    default:

[the sun, 2015/12/11 19:46:29]

RTC_NOTREACHED()

[tommi, 2015/12/12 00:33:11]

this is actually intended (i.e. kInitializing).  Added a comment to clarify.

+      break;
+  }
+  set_state(new_state);
+}
+
+RemoteAudioTrack::~RemoteAudioTrack() {
+  set_state(MediaStreamTrackInterface::kEnded);
+  audio_source_->UnregisterObserver(this);
+}
+
+std::string RemoteAudioTrack::kind() const {
+  return MediaStreamTrackInterface::kAudioKind;
+}
+
+AudioSourceInterface* RemoteAudioTrack::GetSource() const {
+  return audio_source_.get();
+}
+
+void RemoteAudioTrack::AddSink(AudioTrackSinkInterface* sink) {
+  audio_source_->AddSink(sink);
+}
+
+void RemoteAudioTrack::RemoveSink(AudioTrackSinkInterface* sink) {
+  audio_source_->RemoveSink(sink);
+}
+
+bool RemoteAudioTrack::GetSignalLevel(int* level) {
+  return false;
+}
+
+void RemoteAudioTrack::OnChanged() {
+  if (audio_source_->state() == MediaSourceInterface::kEnded)
+    set_state(MediaStreamTrackInterface::kEnded);
+}
+
+}  // namespace webrtc