Reland of Make RtcEventLogImpl to use a TaskQueue instead of a helper-thread

webrtc/pc/peerconnectionfactory.h

 /*
  *  Copyright 2011 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 103 matching lines @@
       rtc::scoped_refptr<webrtc::AudioDecoderFactory> audio_decoder_factory,
       cricket::WebRtcVideoEncoderFactory* video_encoder_factory,
       cricket::WebRtcVideoDecoderFactory* video_decoder_factory,
       rtc::scoped_refptr<AudioMixer> audio_mixer,
       std::unique_ptr<cricket::MediaEngineInterface> media_engine,
       std::unique_ptr<webrtc::CallFactoryInterface> call_factory,
       std::unique_ptr<RtcEventLogFactoryInterface> event_log_factory);
   virtual ~PeerConnectionFactory();
 
  private:
+  std::unique_ptr<RtcEventLog> CreateRtcEventLog_w();
   std::unique_ptr<Call> CreateCall_w(RtcEventLog* event_log);
 
   bool wraps_current_thread_;
   rtc::Thread* network_thread_;
   rtc::Thread* worker_thread_;
   rtc::Thread* signaling_thread_;
   std::unique_ptr<rtc::Thread> owned_network_thread_;
   std::unique_ptr<rtc::Thread> owned_worker_thread_;
   Options options_;
   // External Audio device used for audio playback.
@@ skipping 13 matching lines @@
   // will be created and used.
   rtc::scoped_refptr<AudioMixer> external_audio_mixer_;
   std::unique_ptr<cricket::MediaEngineInterface> media_engine_;
   std::unique_ptr<webrtc::CallFactoryInterface> call_factory_;
   std::unique_ptr<RtcEventLogFactoryInterface> event_log_factory_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_PC_PEERCONNECTIONFACTORY_H_