[Tracing] Use TracingCategoryObserver in runtime statistics

src/log.cc

Index: src/log.cc
diff --git a/src/log.cc b/src/log.cc
index 004d5176b12802d4497c551b510479f52dedbcd2..774dbd5dfff85dc4baf23e2b1691ffbda10446c9 100644
--- a/src/log.cc
+++ b/src/log.cc
@@ -8,6 +8,7 @@
 #include <memory>
 #include <sstream>
 
+#include "include/v8-tracing.h"
 #include "src/bailout-reason.h"
 #include "src/base/platform/platform.h"
 #include "src/bootstrapper.h"
@@ -1283,7 +1284,8 @@ void Logger::RuntimeCallTimerEvent() {
 
 void Logger::TickEvent(v8::TickSample* sample, bool overflow) {
   if (!log_->IsEnabled() || !FLAG_prof_cpp) return;
-  if (FLAG_runtime_call_stats) {
+  if (V8_UNLIKELY(FLAG_runtime_stats ==

[alph, 2016/10/31 20:43:54]

ditto

[lpy, 2016/10/31 20:54:19]

No we don't want to print counters if tracing is enabled, tracing will have a
higher priority, that means when tracing and command line are enabled, we ignore
command line.

+                  v8::tracing::TracingCategoryObserver::ENABLED_BY_NATIVE)) {
     RuntimeCallTimerEvent();
   }
   Log::MessageBuilder msg(log_);