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

webrtc/logging/rtc_event_log/rtc_event_log.h

 /*
  *  Copyright (c) 2015 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 152 matching lines @@
                                       int min_probes,
                                       int min_bytes) = 0;
 
   // Logs the result of a successful probing attempt.
   virtual void LogProbeResultSuccess(int id, int bitrate_bps) = 0;
 
   // Logs the result of an unsuccessful probing attempt.
   virtual void LogProbeResultFailure(int id,
                                      ProbeFailureReason failure_reason) = 0;
 
+  // Logs the result of a host lookup.
+  virtual void LogHostLookupResult(int error,

[Taylor Brandstetter, 2017/08/29 02:30:56]

Can this comment document what "error" is? It looks like it's 0 on success, -1
on generic failure or "no address available for desired address family", and
otherwise is a "getaddrinfo" error code.

[jonaso1, 2017/08/29 10:18:28]

Done.

+                                   int64_t elapsed_time_in_milliseconds) = 0;
+
   // Reads an RtcEventLog file and returns true when reading was successful.
   // The result is stored in the given EventStream object.
   // The order of the events in the EventStream is implementation defined.
   // The current implementation writes a LOG_START event, then the old
   // configurations, then the remaining events in timestamp order and finally
   // a LOG_END event. However, this might change without further notice.
   // TODO(terelius): Change result type to a vector?
   static bool ParseRtcEventLog(const std::string& file_name,
                                rtclog::EventStream* result);
 };
@@ skipping 34 matching lines @@
                               BandwidthUsage detector_state) override {}
   void LogAudioNetworkAdaptation(
       const AudioEncoderRuntimeConfig& config) override {}
   void LogProbeClusterCreated(int id,
                               int bitrate_bps,
                               int min_probes,
                               int min_bytes) override{};
   void LogProbeResultSuccess(int id, int bitrate_bps) override{};
   void LogProbeResultFailure(int id,
                              ProbeFailureReason failure_reason) override{};
+
+  void LogHostLookupResult(int error,
+                           int64_t elapsed_time_in_milliseconds) override {}
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_LOGGING_RTC_EVENT_LOG_RTC_EVENT_LOG_H_