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

webrtc/voice_engine/channel.cc

Index: webrtc/voice_engine/channel.cc
diff --git a/webrtc/voice_engine/channel.cc b/webrtc/voice_engine/channel.cc
index 5732e8e52349a8737be31983c12a7e69d33beec1..38e4d8b1a8fb2b62b6fd61d9a5b3bfcef2c5f873 100644
--- a/webrtc/voice_engine/channel.cc
+++ b/webrtc/voice_engine/channel.cc
@@ -186,6 +186,13 @@ class RtcEventLogProxy final : public webrtc::RtcEventLog {
     }
   };
 
+  void LogHostLookupResult(const std::string& hostname,
+                           int error,
+                           const std::string& result,
+                           int64_t elapsed_time_in_microseconds) override {
+    RTC_NOTREACHED();
+  }
+
   void SetEventLog(RtcEventLog* event_log) {
     rtc::CritScope lock(&crit_);
     event_log_ = event_log;