Added a callback function OnAddTrack to PeerConnectionObserver

webrtc/api/android/jni/peerconnection_jni.cc

 /*
  *  Copyright 2013 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 356 matching lines @@
   }
 
   void OnRenegotiationNeeded() override {
     ScopedLocalRefFrame local_ref_frame(jni());
     jmethodID m =
         GetMethodID(jni(), *j_observer_class_, "onRenegotiationNeeded", "()V");
     jni()->CallVoidMethod(*j_observer_global_, m);
     CHECK_EXCEPTION(jni()) << "error during CallVoidMethod";
   }
 
+  void OnAddTrack(
+      rtc::scoped_refptr<RtpReceiverInterface> receiver,
+      std::vector<rtc::scoped_refptr<MediaStreamInterface>> streams) override {}
+
   void SetConstraints(ConstraintsWrapper* constraints) {
     RTC_CHECK(!constraints_.get()) << "constraints already set!";
     constraints_.reset(constraints);
   }
 
   const ConstraintsWrapper* constraints() { return constraints_.get(); }
 
  private:
   typedef std::map<MediaStreamInterface*, jobject> NativeToJavaStreamsMap;
 
@@ skipping 2018 matching lines @@
   return JavaStringFromStdString(
       jni,
       reinterpret_cast<RtpReceiverInterface*>(j_rtp_receiver_pointer)->id());
 }
 
 JOW(void, RtpReceiver_free)(JNIEnv* jni, jclass, jlong j_rtp_receiver_pointer) {
   reinterpret_cast<RtpReceiverInterface*>(j_rtp_receiver_pointer)->Release();
 }
 
 }  // namespace webrtc_jni