Build WebRTC with data channel only.

webrtc/pc/mediasession.cc

Index: webrtc/pc/mediasession.cc
diff --git a/webrtc/pc/mediasession.cc b/webrtc/pc/mediasession.cc
index 34ccdce7756b343d7c4ceb2cdc60aee2e1f986bf..92ff578d1d03c00d4aade7c5805abc5d46f91ded 100644
--- a/webrtc/pc/mediasession.cc
+++ b/webrtc/pc/mediasession.cc
@@ -784,6 +784,7 @@ template <class C>
 static void NegotiateCodecs(const std::vector<C>& local_codecs,
                             const std::vector<C>& offered_codecs,
                             std::vector<C>* negotiated_codecs) {
+#if defined(HAVE_WEBRTC_VOICE) && defined(HAVE_WEBRTC_VIDEO)
   for (const C& ours : local_codecs) {
     C theirs;
     // Note that we intentionally only find one matching codec for each of our
@@ -821,6 +822,7 @@ static void NegotiateCodecs(const std::vector<C>& local_codecs,
               return payload_type_preferences[a.id] >
                      payload_type_preferences[b.id];
             });
+#endif
 }
 
 // Finds a codec in |codecs2| that matches |codec_to_match|, which is
@@ -1266,6 +1268,7 @@ MediaSessionDescriptionFactory::MediaSessionDescriptionFactory(
     : secure_(SEC_DISABLED),
       add_legacy_(true),
       transport_desc_factory_(transport_desc_factory) {
+#if defined(HAVE_WEBRTC_VOICE) && defined(HAVE_WEBRTC_VIDEO)
   channel_manager->GetSupportedAudioSendCodecs(&audio_send_codecs_);
   channel_manager->GetSupportedAudioReceiveCodecs(&audio_recv_codecs_);
   channel_manager->GetSupportedAudioRtpHeaderExtensions(&audio_rtp_extensions_);
@@ -1274,6 +1277,7 @@ MediaSessionDescriptionFactory::MediaSessionDescriptionFactory(
   channel_manager->GetSupportedDataCodecs(&data_codecs_);
   NegotiateCodecs(audio_recv_codecs_, audio_send_codecs_,
                   &audio_sendrecv_codecs_);
+#endif
 }
 
 const AudioCodecs& MediaSessionDescriptionFactory::audio_sendrecv_codecs()