Build WebRTC with data channel only.

webrtc/pc/mediacontroller.cc

Index: webrtc/pc/mediacontroller.cc
diff --git a/webrtc/pc/mediacontroller.cc b/webrtc/pc/mediacontroller.cc
index fa8acadddcc5229b7126c4b4c2c9cdc7b34b25fb..32d8bd1a68ae5ed259cf9b1b23f9981e9170c4ab 100644
--- a/webrtc/pc/mediacontroller.cc
+++ b/webrtc/pc/mediacontroller.cc
@@ -37,7 +37,9 @@ class MediaController : public webrtc::MediaControllerInterface,
         channel_manager_(channel_manager),
         call_config_(event_log) {
     RTC_DCHECK(worker_thread);
+#ifdef HAVE_MEDIA
     RTC_DCHECK(event_log);
+#endif
     worker_thread_->Invoke<void>(RTC_FROM_HERE,
                                  rtc::Bind(&MediaController::Construct_w, this,
                                            channel_manager_->media_engine()));
@@ -53,9 +55,11 @@ class MediaController : public webrtc::MediaControllerInterface,
   }
   webrtc::Call* call_w() override {
     RTC_DCHECK(worker_thread_->IsCurrent());
+#ifdef HAVE_MEDIA
     if (!call_) {
       call_.reset(webrtc::Call::Create(call_config_));
     }
+#endif
     return call_.get();
   }
   cricket::ChannelManager* channel_manager() const override {
@@ -66,8 +70,10 @@ class MediaController : public webrtc::MediaControllerInterface,
  private:
   void Construct_w(cricket::MediaEngineInterface* media_engine) {
     RTC_DCHECK(worker_thread_->IsCurrent());
+#ifdef HAVE_MEDIA
     RTC_DCHECK(media_engine);
     call_config_.audio_state = media_engine->GetAudioState();
+#endif
     call_config_.bitrate_config.min_bitrate_bps = kMinBandwidthBps;
     call_config_.bitrate_config.start_bitrate_bps = kStartBandwidthBps;
     call_config_.bitrate_config.max_bitrate_bps = kMaxBandwidthBps;