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..8c7c88bd0088b364e2677c3e13edc0d3382cb15b 100644
--- a/webrtc/voice_engine/channel.cc
+++ b/webrtc/voice_engine/channel.cc
@@ -186,6 +186,11 @@ class RtcEventLogProxy final : public webrtc::RtcEventLog {
     }
   };
 
+  void LogHostLookupResult(int error,
+                           int64_t elapsed_time_in_milliseconds) override {
+    RTC_NOTREACHED();
+  }
+
   void SetEventLog(RtcEventLog* event_log) {
     rtc::CritScope lock(&crit_);
     event_log_ = event_log;