Add logging of host lookups made by TurnPort to the RtcEventLog.

webrtc/logging/rtc_event_log/rtc_event_log.cc

Index: webrtc/logging/rtc_event_log/rtc_event_log.cc
diff --git a/webrtc/logging/rtc_event_log/rtc_event_log.cc b/webrtc/logging/rtc_event_log/rtc_event_log.cc
index e661e679828dc401ede7bfbce978fd09ae040a7b..8e39c4aa3227db6d6b7817e3501efdc383ecf6ce 100644
--- a/webrtc/logging/rtc_event_log/rtc_event_log.cc
+++ b/webrtc/logging/rtc_event_log/rtc_event_log.cc
@@ -94,6 +94,9 @@ class RtcEventLogImpl final : public RtcEventLog {
   void LogProbeResultFailure(int id,
                              ProbeFailureReason failure_reason) override;
 
+  void LogHostLookupResult(int error,
+                           int64_t elapsed_time_in_milliseconds) override;
+
  private:
   // Private constructor to ensure that creation is done by RtcEventLog::Create.
   RtcEventLogImpl();
@@ -565,6 +568,18 @@ void RtcEventLogImpl::LogProbeResult(int id,
   StoreEvent(std::move(event));
 }
 
+void RtcEventLogImpl::LogHostLookupResult(
+    int error,
+    int64_t host_lookup_time_ms) {
+  std::unique_ptr<rtclog::Event> event(new rtclog::Event());
+  event->set_timestamp_us(rtc::TimeMicros());
+  event->set_type(rtclog::Event::HOST_LOOKUP_EVENT);
+  auto result = event->mutable_host_lookup_result();
+  result->set_error(error);
+  result->set_host_lookup_time_ms(host_lookup_time_ms);
+  StoreEvent(std::move(event));
+}
+
 void RtcEventLogImpl::StoreEvent(std::unique_ptr<rtclog::Event> event) {
   RTC_DCHECK(event.get() != nullptr);
   if (!event_queue_.Insert(&event)) {