Build WebRTC with data channel only.

webrtc/pc/peerconnection.h

Index: webrtc/pc/peerconnection.h
diff --git a/webrtc/pc/peerconnection.h b/webrtc/pc/peerconnection.h
index 289a5d87a7c581b90041953deea5e7b5e587f1c4..534e0a505430c986584ea6f2ca8ce2d789bb3c47 100644
--- a/webrtc/pc/peerconnection.h
+++ b/webrtc/pc/peerconnection.h
@@ -63,6 +63,10 @@ class PeerConnection : public PeerConnectionInterface,
  public:
   explicit PeerConnection(PeerConnectionFactory* factory);
 
+  explicit PeerConnection(PeerConnectionFactory* factory,
+                          std::unique_ptr<RtcEventLog> event_log,
+                          Call* call);
+
   bool Initialize(
       const PeerConnectionInterface::RTCConfiguration& configuration,
       std::unique_ptr<cricket::PortAllocator> allocator,
@@ -392,9 +396,6 @@ class PeerConnection : public PeerConnectionInterface,
   // This function should only be called from the worker thread.
   void StopRtcEventLog_w();
 
-  // Creates the |*call_| object. Must only be called from the worker thread.
-  void CreateCall_w();
-
   // Storing the factory as a scoped reference pointer ensures that the memory
   // in the PeerConnectionFactoryImpl remains available as long as the
   // PeerConnection is running. It is passed to PeerConnection as a raw pointer.