Add Java binding for new getStats implementation.

webrtc/sdk/android/src/jni/classreferenceholder.cc

Index: webrtc/sdk/android/src/jni/classreferenceholder.cc
diff --git a/webrtc/sdk/android/src/jni/classreferenceholder.cc b/webrtc/sdk/android/src/jni/classreferenceholder.cc
index b163be1841149a9ebfc8a9a1fa1798a0f2dc747a..b19d8ab91874258b8ab1586b8463a635d9b7ee52 100644
--- a/webrtc/sdk/android/src/jni/classreferenceholder.cc
+++ b/webrtc/sdk/android/src/jni/classreferenceholder.cc
@@ -45,8 +45,15 @@ void FreeGlobalClassReferenceHolder() {
 
 ClassReferenceHolder::ClassReferenceHolder(JNIEnv* jni) {
   LoadClass(jni, "android/graphics/SurfaceTexture");
+  LoadClass(jni, "java/lang/Boolean");
+  LoadClass(jni, "java/lang/Double");
+  LoadClass(jni, "java/lang/Integer");
+  LoadClass(jni, "java/lang/Long");
+  LoadClass(jni, "java/lang/String");
+  LoadClass(jni, "java/math/BigInteger");
   LoadClass(jni, "java/nio/ByteBuffer");
   LoadClass(jni, "java/util/ArrayList");
+  LoadClass(jni, "java/util/TreeMap");
   LoadClass(jni, "org/webrtc/AudioTrack");
   LoadClass(jni, "org/webrtc/Camera1Enumerator");
   LoadClass(jni, "org/webrtc/Camera2Enumerator");
@@ -86,6 +93,8 @@ ClassReferenceHolder::ClassReferenceHolder(JNIEnv* jni) {
   LoadClass(jni, "org/webrtc/PeerConnection$CandidateNetworkPolicy");
   LoadClass(jni, "org/webrtc/PeerConnection$KeyType");
   LoadClass(jni, "org/webrtc/PeerConnection$SignalingState");
+  LoadClass(jni, "org/webrtc/RTCStats");
+  LoadClass(jni, "org/webrtc/RTCStatsReport");
   LoadClass(jni, "org/webrtc/RtpReceiver");
   LoadClass(jni, "org/webrtc/RtpSender");
   LoadClass(jni, "org/webrtc/SessionDescription");