RTCStatsCollector: Utilize network thread to minimize thread hops.

webrtc/api/webrtcsession.cc

Index: webrtc/api/webrtcsession.cc
diff --git a/webrtc/api/webrtcsession.cc b/webrtc/api/webrtcsession.cc
index c5582d3630b7ebdc0644f5a6738ff2bc540d6127..99f2cd1a438c0d6ae7f5fbe78efe68884ebc0bfd 100644
--- a/webrtc/api/webrtcsession.cc
+++ b/webrtc/api/webrtcsession.cc
@@ -627,6 +627,24 @@ void WebRtcSession::Close() {
   media_controller_->Close();
 }
 
+std::unique_ptr<ChannelNamePairs> WebRtcSession::GetChannelNamePairs() {
+  ASSERT(signaling_thread()->IsCurrent());
+  std::unique_ptr<ChannelNamePairs> channel_name_pairs(new ChannelNamePairs());
+  if (voice_channel()) {
+    channel_name_pairs->voice = rtc::Optional<ChannelNamePair>(ChannelNamePair(
+        voice_channel()->content_name(), voice_channel()->transport_name()));
+  }
+  if (video_channel()) {
+    channel_name_pairs->video = rtc::Optional<ChannelNamePair>(ChannelNamePair(
+        video_channel()->content_name(), video_channel()->transport_name()));
+  }
+  if (data_channel()) {
+    channel_name_pairs->data = rtc::Optional<ChannelNamePair>(ChannelNamePair(
+        data_channel()->content_name(), data_channel()->transport_name()));
+  }
+  return channel_name_pairs;
+}
+
 cricket::BaseChannel* WebRtcSession::GetChannel(
     const std::string& content_name) {
   if (voice_channel() && voice_channel()->content_name() == content_name) {
@@ -1039,6 +1057,46 @@ bool WebRtcSession::GetChannelTransportStats(cricket::BaseChannel* ch,
   return true;
 }
 
+std::unique_ptr<SessionStats> WebRtcSession::GetSessionStats_n(
+    const ChannelNamePairs& channel_name_pairs) {
+  ASSERT(network_thread()->IsCurrent());
+  std::unique_ptr<SessionStats> session_stats(new SessionStats());
+  if (channel_name_pairs.voice) {
+    cricket::TransportStats voice_transport_stats;
+    if (!transport_controller_->GetStats_n(
+        channel_name_pairs.voice->transport_name, &voice_transport_stats)) {
+      return nullptr;
+    }
+    session_stats->proxy_to_transport[channel_name_pairs.voice->content_name] =
+        channel_name_pairs.voice->transport_name;
+    session_stats->transport_stats[channel_name_pairs.voice->transport_name] =
+        std::move(voice_transport_stats);
+  }
+  if (channel_name_pairs.video) {
+    cricket::TransportStats video_transport_stats;
+    if (!transport_controller_->GetStats_n(
+        channel_name_pairs.video->transport_name, &video_transport_stats)) {
+      return nullptr;
+    }
+    session_stats->proxy_to_transport[channel_name_pairs.video->content_name] =
+        channel_name_pairs.video->transport_name;
+    session_stats->transport_stats[channel_name_pairs.video->transport_name] =
+        std::move(video_transport_stats);
+  }
+  if (channel_name_pairs.data) {
+    cricket::TransportStats data_transport_stats;
+    if (!transport_controller_->GetStats_n(
+        channel_name_pairs.data->transport_name, &data_transport_stats)) {
+      return nullptr;
+    }
+    session_stats->proxy_to_transport[channel_name_pairs.data->content_name] =
+        channel_name_pairs.data->transport_name;
+    session_stats->transport_stats[channel_name_pairs.data->transport_name] =
+        std::move(data_transport_stats);
+  }
+  return session_stats;
+}
+
 bool WebRtcSession::GetLocalCertificate(
     const std::string& transport_name,
     rtc::scoped_refptr<rtc::RTCCertificate>* certificate) {
@@ -1047,12 +1105,26 @@ bool WebRtcSession::GetLocalCertificate(
                                                     certificate);
 }
 
+bool WebRtcSession::GetLocalCertificate_n(
+    const std::string& transport_name,
+    rtc::scoped_refptr<rtc::RTCCertificate>* certificate) {
+  ASSERT(network_thread()->IsCurrent());
+  return transport_controller_->GetLocalCertificate_n(transport_name,
+                                                      certificate);
+}
+
 std::unique_ptr<rtc::SSLCertificate> WebRtcSession::GetRemoteSSLCertificate(
     const std::string& transport_name) {
   ASSERT(signaling_thread()->IsCurrent());
   return transport_controller_->GetRemoteSSLCertificate(transport_name);
 }
 
+std::unique_ptr<rtc::SSLCertificate> WebRtcSession::GetRemoteSSLCertificate_n(
+    const std::string& transport_name) {
+  ASSERT(network_thread()->IsCurrent());
+  return transport_controller_->GetRemoteSSLCertificate_n(transport_name);
+}
+
 bool WebRtcSession::EnableBundle(const cricket::ContentGroup& bundle) {
   const std::string* first_content_name = bundle.FirstContentName();
   if (!first_content_name) {