Add PeerConnectionObserver#onRemoveTrack to android sdk

webrtc/sdk/android/src/jni/pc/peerconnectionobserver_jni.h

Index: webrtc/sdk/android/src/jni/pc/peerconnectionobserver_jni.h
diff --git a/webrtc/sdk/android/src/jni/pc/peerconnectionobserver_jni.h b/webrtc/sdk/android/src/jni/pc/peerconnectionobserver_jni.h
index 2d9d749a6b2014f43820549c06da9d85d400d107..58994709aa0f270c22a2aed51b51236b36080e16 100644
--- a/webrtc/sdk/android/src/jni/pc/peerconnectionobserver_jni.h
+++ b/webrtc/sdk/android/src/jni/pc/peerconnectionobserver_jni.h
@@ -11,6 +11,7 @@
 #ifndef WEBRTC_SDK_ANDROID_SRC_JNI_PC_PEERCONNECTIONOBSERVER_JNI_H_
 #define WEBRTC_SDK_ANDROID_SRC_JNI_PC_PEERCONNECTIONOBSERVER_JNI_H_
 
+#include <webrtc/pc/mediastreamobserver.h>
 #include <map>
 #include <memory>
 #include <vector>
@@ -24,7 +25,8 @@ namespace webrtc_jni {
 // Adapter between the C++ PeerConnectionObserver interface and the Java
 // PeerConnection.Observer interface.  Wraps an instance of the Java interface
 // and dispatches C++ callbacks to Java.
-class PeerConnectionObserverJni : public webrtc::PeerConnectionObserver {
+class PeerConnectionObserverJni : public webrtc::PeerConnectionObserver,
+                                  public sigslot::has_slots<> {
  public:
   PeerConnectionObserverJni(JNIEnv* jni, jobject j_observer);
   virtual ~PeerConnectionObserverJni();
@@ -61,9 +63,15 @@ class PeerConnectionObserverJni : public webrtc::PeerConnectionObserver {
       NativeToJavaStreamsMap;
   typedef std::map<webrtc::RtpReceiverInterface*, jobject>
       NativeToJavaRtpReceiverMap;
+  typedef std::map<webrtc::MediaStreamTrackInterface*, jobject>
+      NativeToJavaMediaTrackMap;
+  typedef std::map<webrtc::MediaStreamTrackInterface*,
+                   webrtc::RtpReceiverInterface*>
+      NativeMediaStreamTrackToNativeRtpReceiver;
 
   void DisposeRemoteStream(const NativeToJavaStreamsMap::iterator& it);
   void DisposeRtpReceiver(const NativeToJavaRtpReceiverMap::iterator& it);
+  void DisposeRemoteTrack(const NativeToJavaMediaTrackMap::iterator& it);
 
   // If the NativeToJavaStreamsMap contains the stream, return it.
   // Otherwise, create a new Java MediaStream.
@@ -76,6 +84,15 @@ class PeerConnectionObserverJni : public webrtc::PeerConnectionObserver {
       const std::vector<rtc::scoped_refptr<webrtc::MediaStreamInterface>>&
           streams);
 
+  void OnAudioTrackAdded(webrtc::AudioTrackInterface* track,
+                         webrtc::MediaStreamInterface* stream);
+  void OnVideoTrackAdded(webrtc::VideoTrackInterface* track,
+                         webrtc::MediaStreamInterface* stream);
+  void OnAudioTrackRemoved(webrtc::AudioTrackInterface* track,
+                           webrtc::MediaStreamInterface* stream);
+  void OnVideoTrackRemoved(webrtc::VideoTrackInterface* track,
+                           webrtc::MediaStreamInterface* stream);
+
   const ScopedGlobalRef<jobject> j_observer_global_;
   const ScopedGlobalRef<jclass> j_observer_class_;
   const ScopedGlobalRef<jclass> j_media_stream_class_;
@@ -88,11 +105,15 @@ class PeerConnectionObserverJni : public webrtc::PeerConnectionObserver {
   const jmethodID j_data_channel_ctor_;
   const ScopedGlobalRef<jclass> j_rtp_receiver_class_;
   const jmethodID j_rtp_receiver_ctor_;
+
   // C++ -> Java remote streams. The stored jobects are global refs and must be
   // manually deleted upon removal. Use DisposeRemoteStream().
   NativeToJavaStreamsMap remote_streams_;
-  NativeToJavaRtpReceiverMap rtp_receivers_;
   std::unique_ptr<MediaConstraintsJni> constraints_;
+  NativeToJavaRtpReceiverMap rtp_receivers_;
+  NativeMediaStreamTrackToNativeRtpReceiver track_to_receiver_;
+  std::vector<std::unique_ptr<webrtc::MediaStreamObserver>> stream_observers_;
+  NativeToJavaMediaTrackMap remote_tracks_;
 };
 
 }  // namespace webrtc_jni