Don't allow changing ICE pool size after SetLocalDescription.

webrtc/api/peerconnection.cc

 /*
  *  Copyright 2012 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 1250 matching lines @@
   signaling_thread()->Post(RTC_FROM_HERE, this,
                            MSG_SET_SESSIONDESCRIPTION_SUCCESS, msg);
 }
 
 PeerConnectionInterface::RTCConfiguration PeerConnection::GetConfiguration() {
   return configuration_;
 }
 
 bool PeerConnection::SetConfiguration(const RTCConfiguration& configuration) {
   TRACE_EVENT0("webrtc", "PeerConnection::SetConfiguration");
+
+  if (session_->local_description() &&
+      configuration.ice_candidate_pool_size !=
+          configuration_.ice_candidate_pool_size) {
+    LOG(LS_ERROR) << "Can't change candidate pool size after calling "
+                     "SetLocalDescription.";
+    return false;
+  }
   // TODO(deadbeef): Return false and log an error if there are any unsupported
   // modifications.
   if (port_allocator_) {
     if (!network_thread()->Invoke<bool>(
             RTC_FROM_HERE,
             rtc::Bind(&PeerConnection::ReconfigurePortAllocator_n, this,
                       configuration))) {
+      LOG(LS_ERROR) << "Failed to apply configuration to PortAllocator.";
       return false;
     }
   }
 
   // TODO(deadbeef): Shouldn't have to hop to the worker thread twice...
   session_->SetIceConfig(session_->ParseIceConfig(configuration));
 
   configuration_ = configuration;
   return true;
 }
@@ skipping 1064 matching lines @@
     const RTCConfiguration& configuration) {
   cricket::ServerAddresses stun_servers;
   std::vector<cricket::RelayServerConfig> turn_servers;
   if (!ParseIceServers(configuration.servers, &stun_servers, &turn_servers)) {
     return false;
   }
   port_allocator_->set_candidate_filter(
       ConvertIceTransportTypeToCandidateFilter(configuration.type));
   // Call this last since it may create pooled allocator sessions using the
   // candidate filter set above.
-  port_allocator_->SetConfiguration(stun_servers, turn_servers,
-                                    configuration.ice_candidate_pool_size,
-                                    configuration.prune_turn_ports);
-  return true;
+  return port_allocator_->SetConfiguration(
+      stun_servers, turn_servers, configuration.ice_candidate_pool_size,
+      configuration.prune_turn_ports);
 }
 
 bool PeerConnection::StartRtcEventLog_w(rtc::PlatformFile file,
                                         int64_t max_size_bytes) {
   return event_log_->StartLogging(file, max_size_bytes);
 }
 
 void PeerConnection::StopRtcEventLog_w() {
   event_log_->StopLogging();
 }
 }  // namespace webrtc