Remove candidates when doing continual gathering

webrtc/api/webrtcsession.cc

Index: webrtc/api/webrtcsession.cc
diff --git a/webrtc/api/webrtcsession.cc b/webrtc/api/webrtcsession.cc
index 2f3c911454d440d448f5f4d6c68a498a7ef246fd..5c34e961d6373da291eac3f9dc99b1b8b7792c4e 100644
--- a/webrtc/api/webrtcsession.cc
+++ b/webrtc/api/webrtcsession.cc
@@ -501,6 +501,8 @@ WebRtcSession::WebRtcSession(webrtc::MediaControllerInterface* media_controller,
       this, &WebRtcSession::OnTransportControllerGatheringState);
   transport_controller_->SignalCandidatesGathered.connect(
       this, &WebRtcSession::OnTransportControllerCandidatesGathered);
+  transport_controller_->SignalCandidatesRemoved.connect(
+      this, &WebRtcSession::OnTransportControllerCandidatesRemoved);
 }
 
 WebRtcSession::~WebRtcSession() {
@@ -1086,7 +1088,7 @@ bool WebRtcSession::ProcessIceMessage(const IceCandidateInterface* candidate) {
   if (!remote_desc_) {
     LOG(LS_ERROR) << "ProcessIceMessage: ICE candidates can't be added "
                   << "without any remote session description.";
-     return false;
+    return false;
   }
 
   if (!candidate) {
@@ -1114,6 +1116,35 @@ bool WebRtcSession::ProcessIceMessage(const IceCandidateInterface* candidate) {
   }
 }
 
+bool WebRtcSession::RemoveRemoteIceCandidates(
+    const std::vector<cricket::Candidate>& candidates) {
+  if (!remote_desc_) {
+    LOG(LS_ERROR) << "RemoveRemoteIceCandidates: ICE candidates can't be "
+                  << "removed without any remote session description.";
+    return false;
+  }
+
+  if (candidates.empty()) {
+    LOG(LS_ERROR) << "RemoveRemoteIceCandidates: candidates are empty.";
+    return false;
+  }
+
+  size_t number_removed = remote_desc_->RemoveCandidates(candidates);
+  if (number_removed != candidates.size()) {
+    LOG(LS_ERROR) << "RemoveRemoteIceCandidates: Failed to remove candidates. "
+                  << "Requested " << candidates.size() << " but only "
+                  << number_removed << " are removed.";
+  }
+
+  // Remove the candidates from the transport controller.
+  std::string error;
+  bool res = transport_controller_->RemoveRemoteCandidates(candidates, &error);
+  if (!res) {
+    LOG(LS_ERROR) << "Error when removing remote candidates: " << error;
+  }
+  return res;
+}
+
 bool WebRtcSession::SetIceTransports(
     PeerConnectionInterface::IceTransportsType type) {
   return port_allocator()->set_candidate_filter(
@@ -1523,6 +1554,27 @@ void WebRtcSession::OnTransportControllerCandidatesGathered(
   }
 }
 
+void WebRtcSession::OnTransportControllerCandidatesRemoved(
+    const std::vector<cricket::Candidate>& candidates) {
+  ASSERT(signaling_thread()->IsCurrent());
+  // Sanity check.
+  for (const cricket::Candidate& candidate : candidates) {
+    if (candidate.transport_name().empty()) {
+      LOG(LS_ERROR) << "OnTransportControllerCandidatesRemoved: "
+                    << "empty content name in candidate "
+                    << candidate.ToString();
+      return;
+    }
+  }
+
+  if (local_desc_) {
+    local_desc_->RemoveCandidates(candidates);
+  }
+  if (ice_observer_) {
+    ice_observer_->OnIceCandidatesRemoved(candidates);
+  }
+}
+
 // Enabling voice and video channel.
 void WebRtcSession::EnableChannels() {
   if (voice_channel_ && !voice_channel_->enabled())
@@ -1582,14 +1634,11 @@ bool WebRtcSession::UseCandidatesInSessionDescription(
   return ret;
 }
 
-bool WebRtcSession::UseCandidate(
-    const IceCandidateInterface* candidate) {
-
+bool WebRtcSession::UseCandidate(const IceCandidateInterface* candidate) {
   size_t mediacontent_index = static_cast<size_t>(candidate->sdp_mline_index());
   size_t remote_content_size = remote_desc_->description()->contents().size();
   if (mediacontent_index >= remote_content_size) {
-    LOG(LS_ERROR)
-        << "UseRemoteCandidateInSession: Invalid candidate media index.";
+    LOG(LS_ERROR) << "UseCandidate: Invalid candidate media index.";
     return false;
   }