Revert of Remove AudioTrackRenderer

talk/media/webrtc/webrtcvoiceengine.cc

 /*
  * libjingle
  * Copyright 2004 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 1287 matching lines @@
   // callback.
   // This method is called on the libjingle worker thread.
   // TODO(xians): Make sure Start() is called only once.
   void Start(AudioRenderer* renderer) {
     rtc::CritScope lock(&lock_);
     RTC_DCHECK(renderer != NULL);
     if (renderer_ != NULL) {
       RTC_DCHECK(renderer_ == renderer);
       return;
     }
+
+    // TODO(xians): Remove AddChannel() call after Chrome turns on APM
+    // in getUserMedia by default.
+    renderer->AddChannel(channel_);
     renderer->SetSink(this);
     renderer_ = renderer;
   }
 
   // Stops rendering by setting the sink of the renderer to NULL. No data
   // callback will be received after this method.
   // This method is called on the libjingle worker thread.
   void Stop() {
     rtc::CritScope lock(&lock_);
-    if (renderer_ != NULL) {
-      renderer_->SetSink(NULL);
-      renderer_ = NULL;
-    }
+    if (renderer_ == NULL)
+      return;
+
+    renderer_->RemoveChannel(channel_);
+    renderer_->SetSink(NULL);
+    renderer_ = NULL;
   }
 
   // AudioRenderer::Sink implementation.
   // This method is called on the audio thread.
   void OnData(const void* audio_data,
               int bits_per_sample,
               int sample_rate,
               int number_of_channels,
               size_t number_of_frames) override {
     voe_audio_transport_->OnData(channel_,
@@ skipping 1883 matching lines @@
       LOG(LS_WARNING) << "Unknown codec " << ToString(codec);
       return false;
     }
   }
   return true;
 }
 
 }  // namespace cricket
 
 #endif  // HAVE_WEBRTC_VOICE