Build WebRTC with data channel only.

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 88 matching lines @@
       cricket::PortAllocator* port_allocator,
       bool redetermine_role_on_ice_restart);
   virtual cricket::ChannelManager* channel_manager();
   virtual rtc::Thread* signaling_thread();
   virtual rtc::Thread* worker_thread();
   virtual rtc::Thread* network_thread();
   const Options& options() const { return options_; }
 
  protected:
   PeerConnectionFactory(
-      rtc::scoped_refptr<webrtc::AudioEncoderFactory> audio_encoder_factory,
-      rtc::scoped_refptr<webrtc::AudioDecoderFactory> audio_decoder_factory);
-  PeerConnectionFactory(
       rtc::Thread* network_thread,
       rtc::Thread* worker_thread,
       rtc::Thread* signaling_thread,
       AudioDeviceModule* default_adm,
       rtc::scoped_refptr<webrtc::AudioEncoderFactory> audio_encoder_factory,
       rtc::scoped_refptr<webrtc::AudioDecoderFactory> audio_decoder_factory,
       cricket::WebRtcVideoEncoderFactory* video_encoder_factory,
       cricket::WebRtcVideoDecoderFactory* video_decoder_factory,
-      rtc::scoped_refptr<AudioMixer> audio_mixer);
+      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<cricket::MediaEngineInterface> CreateMediaEngine_w();
+  std::unique_ptr<Call> CreateCall_w(RtcEventLog* event_log);
 
-  bool owns_ptrs_;
   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_;
+  std::unique_ptr<rtc::Thread> owned_signaling_thread_;

[Taylor Brandstetter, 2017/06/15 00:35:02]

|owned_signaling_thread_| isn't used, because rather than the signaling thread
being created/destroyed, it's wrapped/unwrapped, which is kept track of by
|wraps_current_thread_|.

   Options options_;
   // External Audio device used for audio playback.
   rtc::scoped_refptr<AudioDeviceModule> default_adm_;
   rtc::scoped_refptr<AudioEncoderFactory> audio_encoder_factory_;
   rtc::scoped_refptr<AudioDecoderFactory> audio_decoder_factory_;
   std::unique_ptr<cricket::ChannelManager> channel_manager_;
   // External Video encoder factory. This can be NULL if the client has not
   // injected any. In that case, video engine will use the internal SW encoder.
   std::unique_ptr<cricket::WebRtcVideoEncoderFactory> video_encoder_factory_;
   // External Video decoder factory. This can be NULL if the client has not
   // injected any. In that case, video engine will use the internal SW decoder.
   std::unique_ptr<cricket::WebRtcVideoDecoderFactory> video_decoder_factory_;
   std::unique_ptr<rtc::BasicNetworkManager> default_network_manager_;
   std::unique_ptr<rtc::BasicPacketSocketFactory> default_socket_factory_;
   // External audio mixer. This can be NULL. In that case, internal audio mixer
   // 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_