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();

[terelius, 2017/08/18 11:41:33]

The rest of the code has forwarded the call, regardless of whether the function
is expected to be called via the voice engine or not. On the other hand, it
makes sense to catch unexpected calls. One of the owners need to decide what the
policy should be here.

+  }
+
   void SetEventLog(RtcEventLog* event_log) {
     rtc::CritScope lock(&crit_);
     event_log_ = event_log;