Build WebRTC with data channel only.

webrtc/pc/peerconnectionfactory.cc

Index: webrtc/pc/peerconnectionfactory.cc
diff --git a/webrtc/pc/peerconnectionfactory.cc b/webrtc/pc/peerconnectionfactory.cc
index 777bac1eb59aadd49bcc9af1d44ac66e9d02276f..c68ecf8dda411d24f95a2c2d3e99c75cd54b8ef0 100644
--- a/webrtc/pc/peerconnectionfactory.cc
+++ b/webrtc/pc/peerconnectionfactory.cc
@@ -54,12 +54,6 @@ rtc::scoped_refptr<PeerConnectionFactoryInterface> CreatePeerConnectionFactory(
                                             pc_factory);
 }
 
-rtc::scoped_refptr<PeerConnectionFactoryInterface>
-CreatePeerConnectionFactory() {
-  return CreatePeerConnectionFactory(CreateBuiltinAudioEncoderFactory(),
-                                     CreateBuiltinAudioDecoderFactory());
-}
-
 rtc::scoped_refptr<PeerConnectionFactoryInterface> CreatePeerConnectionFactory(
     rtc::Thread* network_thread,
     rtc::Thread* worker_thread,
@@ -116,21 +110,6 @@ CreatePeerConnectionFactoryWithAudioMixer(
   return PeerConnectionFactoryProxy::Create(signaling_thread, pc_factory);
 }
 
-rtc::scoped_refptr<PeerConnectionFactoryInterface>
-CreatePeerConnectionFactoryWithAudioMixer(
-    rtc::Thread* network_thread,
-    rtc::Thread* worker_thread,
-    rtc::Thread* signaling_thread,
-    AudioDeviceModule* default_adm,
-    cricket::WebRtcVideoEncoderFactory* encoder_factory,
-    cricket::WebRtcVideoDecoderFactory* decoder_factory,
-    rtc::scoped_refptr<AudioMixer> audio_mixer) {
-  return CreatePeerConnectionFactoryWithAudioMixer(
-      network_thread, worker_thread, signaling_thread, default_adm,
-      CreateBuiltinAudioEncoderFactory(), CreateBuiltinAudioDecoderFactory(),
-      encoder_factory, decoder_factory, audio_mixer);
-}
-
 PeerConnectionFactory::PeerConnectionFactory(
     rtc::scoped_refptr<webrtc::AudioEncoderFactory> audio_encoder_factory,
     rtc::scoped_refptr<webrtc::AudioDecoderFactory> audio_decoder_factory)