Add ExternalTimerEventScope to log non internal timer events scopes

src/log.cc

Index: src/log.cc
diff --git a/src/log.cc b/src/log.cc
index e8af5d0ff4aa02d7667c3e27b2bb4846f61f5517..ad6019e52bf326e040bc4562276e034b6abb72c2 100644
--- a/src/log.cc
+++ b/src/log.cc
@@ -1123,6 +1123,12 @@ void Logger::TimerEventScope::LogTimerEvent(StartEnd se) {
 }
 
 
+void Logger::ExternalTimerEventScope::LogTimerEvent(StartEnd se) {
+  if (FLAG_log_timer_events)
+    isolate_->event_logger()(name_, se);
+}
+
+
 const char* Logger::TimerEventScope::v8_recompile_synchronous =
     "V8.RecompileSynchronous";
 const char* Logger::TimerEventScope::v8_recompile_concurrent =