Remove candidates when doing continual gathering

webrtc/api/java/jni/peerconnection_jni.cc

Index: webrtc/api/java/jni/peerconnection_jni.cc
diff --git a/webrtc/api/java/jni/peerconnection_jni.cc b/webrtc/api/java/jni/peerconnection_jni.cc
index f7b9e90202c7a4179f25079018f2e313aef0a947..816df8f41be3392613f5ed94c9f04bc773bee8b9 100644
--- a/webrtc/api/java/jni/peerconnection_jni.cc
+++ b/webrtc/api/java/jni/peerconnection_jni.cc
@@ -91,6 +91,7 @@ using webrtc::DataChannelInit;
 using webrtc::DataChannelInterface;
 using webrtc::DataChannelObserver;
 using webrtc::IceCandidateInterface;
+using webrtc::IceCandidateInterfaceRefPtr;
 using webrtc::LogcatTraceContext;
 using webrtc::MediaConstraintsInterface;
 using webrtc::MediaSourceInterface;
@@ -188,22 +189,25 @@ class PCOJava : public PeerConnectionObserver {
 
   void OnIceCandidate(const IceCandidateInterface* candidate) override {
     ScopedLocalRefFrame local_ref_frame(jni());
-    std::string sdp;
-    RTC_CHECK(candidate->ToString(&sdp)) << "got so far: " << sdp;
     jclass candidate_class = FindClass(jni(), "org/webrtc/IceCandidate");
-    jmethodID ctor = GetMethodID(jni(), candidate_class,
-        "<init>", "(Ljava/lang/String;ILjava/lang/String;)V");
-    jstring j_mid = JavaStringFromStdString(jni(), candidate->sdp_mid());
-    jstring j_sdp = JavaStringFromStdString(jni(), sdp);
-    jobject j_candidate = jni()->NewObject(
-        candidate_class, ctor, j_mid, candidate->sdp_mline_index(), j_sdp);
-    CHECK_EXCEPTION(jni()) << "error during NewObject";
+    jobject j_candidate = ToJavaCandidate(jni(), &candidate_class, candidate);
     jmethodID m = GetMethodID(jni(), *j_observer_class_,
                               "onIceCandidate", "(Lorg/webrtc/IceCandidate;)V");
     jni()->CallVoidMethod(*j_observer_global_, m, j_candidate);
     CHECK_EXCEPTION(jni()) << "error during CallVoidMethod";
   }
 
+  void OnIceCandidatesRemoved(
+      const std::vector<IceCandidateInterfaceRefPtr>& candidates) {
+    ScopedLocalRefFrame local_ref_frame(jni());
+    jobjectArray candidates_array = ToJavaCandidateArray(jni(), candidates);
+    jmethodID m =
+        GetMethodID(jni(), *j_observer_class_, "onIceCandidatesRemoved",
+                    "([Lorg/webrtc/IceCandidate;)V");
+    jni()->CallVoidMethod(*j_observer_global_, m, candidates_array);
+    CHECK_EXCEPTION(jni()) << "Error during CallVoidMethod";
+  }
+
   void OnSignalingChange(
       PeerConnectionInterface::SignalingState new_state) override {
     ScopedLocalRefFrame local_ref_frame(jni());
@@ -371,6 +375,36 @@ class PCOJava : public PeerConnectionObserver {
     DeleteGlobalRef(jni(), j_stream);
   }
 
+  jobject ToJavaCandidate(JNIEnv* jni,
+                          jclass* candidate_class,
+                          const IceCandidateInterface* candidate) {
+    std::string sdp;
+    RTC_CHECK(candidate->ToString(&sdp)) << "got so far: " << sdp;
+    jmethodID ctor = GetMethodID(jni, *candidate_class, "<init>",
+                                 "(Ljava/lang/String;ILjava/lang/String;)V");
+    jstring j_mid = JavaStringFromStdString(jni, candidate->sdp_mid());
+    jstring j_sdp = JavaStringFromStdString(jni, sdp);
+    jobject j_candidate = jni->NewObject(*candidate_class, ctor, j_mid,
+                                         candidate->sdp_mline_index(), j_sdp);
+    CHECK_EXCEPTION(jni) << "error during Java Candidate NewObject";
+    return j_candidate;
+  }
+
+  jobjectArray ToJavaCandidateArray(
+      JNIEnv* jni,
+      const std::vector<IceCandidateInterfaceRefPtr>& candidates) {
+    jclass candidate_class = FindClass(jni, "org/webrtc/IceCandidate");
+    jobjectArray java_candidates =
+        jni->NewObjectArray(candidates.size(), candidate_class, NULL);
+    int i = 0;
+    for (const auto candidate : candidates) {
+      jobject j_candidate =
+          ToJavaCandidate(jni, &candidate_class, candidate.get());
+      jni->SetObjectArrayElement(java_candidates, i++, j_candidate);
+    }
+    return java_candidates;
+  }
+
   JNIEnv* jni() {
     return AttachCurrentThreadIfNeeded();
   }
@@ -1724,6 +1758,34 @@ JOW(jboolean, PeerConnection_nativeAddIceCandidate)(
   return ExtractNativePC(jni, j_pc)->AddIceCandidate(candidate.get());
 }
 
+static IceCandidateInterface* GetIceCandidateFromJava(JNIEnv* jni,
+                                                      jobject j_candidate) {
+  jclass j_candidate_class = GetObjectClass(jni, j_candidate);
+  jfieldID j_sdp_mid_id =
+      GetFieldID(jni, j_candidate_class, "sdpMid", "Ljava/lang/String;");
+  std::string sdp_mid =
+      JavaToStdString(jni, GetStringField(jni, j_candidate, j_sdp_mid_id));
+  jfieldID j_sdp_mline_index_id =
+      GetFieldID(jni, j_candidate_class, "sdpMLineIndex", "I");
+  int sdp_mline_index = GetIntField(jni, j_candidate, j_sdp_mline_index_id);
+  jfieldID j_sdp_id =
+      GetFieldID(jni, j_candidate_class, "sdp", "Ljava/lang/String;");
+  std::string sdp =
+      JavaToStdString(jni, GetStringField(jni, j_candidate, j_sdp_id));
+  return webrtc::CreateIceCandidate(sdp_mid, sdp_mline_index, sdp, NULL);
+}
+
+JOW(jboolean, PeerConnection_nativeRemoveIceCandidates)
+(JNIEnv* jni, jobject j_pc, jobjectArray j_candidates) {
+  std::vector<IceCandidateInterfaceRefPtr> candidates;
+  size_t num_candidates = jni->GetArrayLength(j_candidates);
+  for (size_t i = 0; i < num_candidates; ++i) {
+    jobject j_candidate = jni->GetObjectArrayElement(j_candidates, i);
+    candidates.push_back(GetIceCandidateFromJava(jni, j_candidate));
+  }
+  return ExtractNativePC(jni, j_pc)->RemoveIceCandidates(candidates);
+}
+
 JOW(jboolean, PeerConnection_nativeAddLocalStream)(
     JNIEnv* jni, jobject j_pc, jlong native_stream) {
   return ExtractNativePC(jni, j_pc)->AddStream(