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

webrtc/logging/rtc_event_log/rtc_event_log_unittest_helper.h

 /*
  *  Copyright (c) 2016 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 64 matching lines @@
 
   static void VerifyProbeResultSuccess(const ParsedRtcEventLog& parsed_log,
                                        size_t index,
                                        uint32_t id,
                                        uint32_t bitrate_bps);
 
   static void VerifyProbeResultFailure(const ParsedRtcEventLog& parsed_log,
                                        size_t index,
                                        uint32_t id,
                                        ProbeFailureReason failure_reason);
+
+  static void VerifyLogHostLookupEvent(const ParsedRtcEventLog& parsed_log,
+                                       size_t index,
+                                       int error,
+                                       int64_t host_lookup_time_ms);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_LOGGING_RTC_EVENT_LOG_RTC_EVENT_LOG_UNITTEST_HELPER_H_