fix assertion in Logger::CurrentTimeEvent with --prof

src/log.cc

Index: src/log.cc
diff --git a/src/log.cc b/src/log.cc
index 25d38dd8f4ce19ff372a0f830952a069a0cb3879..ec2bb631ea96b9dcfcbeb4abc4443c3691aa57b6 100644
--- a/src/log.cc
+++ b/src/log.cc
@@ -904,7 +904,7 @@ void Logger::CodeDeoptEvent(Code* code, Address pc, int fp_to_sp_delta) {
 
 void Logger::CurrentTimeEvent() {
   if (!log_->IsEnabled()) return;
-  DCHECK(FLAG_log_internal_timer_events);
+  DCHECK(FLAG_log_timer_events || FLAG_prof_cpp);
   Log::MessageBuilder msg(log_);
   int since_epoch = static_cast<int>(timer_.Elapsed().InMicroseconds());
   msg.Append("current-time,%ld", since_epoch);