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

webrtc/logging/rtc_event_log/rtc_event_log2stats.cc

Index: webrtc/logging/rtc_event_log/rtc_event_log2stats.cc
diff --git a/webrtc/logging/rtc_event_log/rtc_event_log2stats.cc b/webrtc/logging/rtc_event_log/rtc_event_log2stats.cc
index 6b21cf1a7ee50a2e15263f1540aacdb5e7388144..346179104d2664ea5ad1a0907ad0d63ec8a2ba95 100644
--- a/webrtc/logging/rtc_event_log/rtc_event_log2stats.cc
+++ b/webrtc/logging/rtc_event_log/rtc_event_log2stats.cc
@@ -160,6 +160,8 @@ std::string EventTypeToString(webrtc::rtclog::Event::EventType event_type) {
       return "BWE_PROBE_CREATED";
     case webrtc::rtclog::Event::BWE_PROBE_RESULT_EVENT:
       return "BWE_PROBE_RESULT";
+    case webrtc::rtclog::Event::HOST_LOOKUP_EVENT:
+      return "HOST_LOOKUP";
   }
   RTC_NOTREACHED();
   return "UNKNOWN_EVENT";