Correct stats for RTCPeerConnectionStats.dataChannels[Opened/Closed].

webrtc/api/peerconnection.cc

Index: webrtc/api/peerconnection.cc
diff --git a/webrtc/api/peerconnection.cc b/webrtc/api/peerconnection.cc
index 830c301a6d9cf0090870e3a06bca4ce23835ec0c..f865cbe79df6e34d061fb8906822e4b00f728930 100644
--- a/webrtc/api/peerconnection.cc
+++ b/webrtc/api/peerconnection.cc
@@ -2079,6 +2079,10 @@ rtc::scoped_refptr<DataChannel> PeerConnection::InternalCreateDataChannel(
     sid_allocator_.ReleaseSid(new_config.id);
     return nullptr;
   }
+  channel->SignalOpened.connect(stats_collector_.get(),
+                                &RTCStatsCollector::OnDataChannelOpened);
+  channel->SignalOpened.connect(stats_collector_.get(),
+                                &RTCStatsCollector::OnDataChannelClosed);
 
   if (channel->data_channel_type() == cricket::DCT_RTP) {
     if (rtp_data_channels_.find(channel->label()) != rtp_data_channels_.end()) {