Split libjingle's signaling thread from the UI thread

content/renderer/media/webrtc/webrtc_local_audio_track_adapter.h

Index: content/renderer/media/webrtc/webrtc_local_audio_track_adapter.h
diff --git a/content/renderer/media/webrtc/webrtc_local_audio_track_adapter.h b/content/renderer/media/webrtc/webrtc_local_audio_track_adapter.h
index e183ebafca7ec04b9bb523995daca3ebf0ffb9e3..52bcd9280592d1effc5fdd969a6769a80fa9edd0 100644
--- a/content/renderer/media/webrtc/webrtc_local_audio_track_adapter.h
+++ b/content/renderer/media/webrtc/webrtc_local_audio_track_adapter.h
@@ -9,6 +9,7 @@
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_vector.h"
+#include "base/single_thread_task_runner.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_checker.h"
 #include "content/common/content_export.h"
@@ -41,7 +42,8 @@ class CONTENT_EXPORT WebRtcLocalAudioTrackAdapter
 
   WebRtcLocalAudioTrackAdapter(
       const std::string& label,
-      webrtc::AudioSourceInterface* track_source);
+      webrtc::AudioSourceInterface* track_source,
+      const scoped_refptr<base::SingleThreadTaskRunner>& signaling_thread);
 
   ~WebRtcLocalAudioTrackAdapter() override;
 
@@ -60,10 +62,11 @@ class CONTENT_EXPORT WebRtcLocalAudioTrackAdapter
   void SetAudioProcessor(
       const scoped_refptr<MediaStreamAudioProcessor>& processor);
 
- private:
   // webrtc::MediaStreamTrack implementation.
   std::string kind() const override;
+  bool set_enabled(bool enable) override;
 
+ private:
   // webrtc::AudioTrackInterface implementation.
   void AddSink(webrtc::AudioTrackSinkInterface* sink) override;
   void RemoveSink(webrtc::AudioTrackSinkInterface* sink) override;
@@ -86,6 +89,9 @@ class CONTENT_EXPORT WebRtcLocalAudioTrackAdapter
   // TODO(xians): merge |track_source_| to |capturer_| in WebRtcLocalAudioTrack.
   rtc::scoped_refptr<webrtc::AudioSourceInterface> track_source_;
 
+  // Libjingle's signaling thread.
+  const scoped_refptr<base::SingleThreadTaskRunner> signaling_thread_;
+
   // The audio processsor that applies audio processing on the data of audio
   // track.
   scoped_refptr<MediaStreamAudioProcessor> audio_processor_;
@@ -101,7 +107,7 @@ class CONTENT_EXPORT WebRtcLocalAudioTrackAdapter
   int signal_level_;
 
   // Thread checker for libjingle's signaling thread.
-  base::ThreadChecker signaling_thread_;
+  base::ThreadChecker signaling_thread_checker_;
   base::ThreadChecker capture_thread_;
 
   // Protects |voe_channels_|, |audio_processor_| and |signal_level_|.