Integrate Chrome tracing with V8 (WIP)

src/counters.cc

Index: src/counters.cc
diff --git a/src/counters.cc b/src/counters.cc
index 972bd6862c0f5a5524dfd9f57021e9eb4b61c1a8..bab748e1640722567f608766c6e6a15dc6697607 100644
--- a/src/counters.cc
+++ b/src/counters.cc
@@ -40,7 +40,7 @@ void HistogramTimer::Start() {
   if (Enabled()) {
     timer_.Start();
   }
-  Logger::CallEventLogger(isolate(), name(), Logger::START, true);
+  Logger::CallEventLogger(isolate(), name(), Logger::START, overhead());
 }
 
 
@@ -51,7 +51,7 @@ void HistogramTimer::Stop() {
     AddSample(static_cast<int>(timer_.Elapsed().InMilliseconds()));
     timer_.Stop();
   }
-  Logger::CallEventLogger(isolate(), name(), Logger::END, true);
+  Logger::CallEventLogger(isolate(), name(), Logger::END, overhead());
 }
 
 
@@ -61,8 +61,8 @@ Counters::Counters(Isolate* isolate) {
   HISTOGRAM_RANGE_LIST(HR)
 #undef HR
 
-#define HT(name, caption) \
-    name##_ = HistogramTimer(#caption, 0, 10000, 50, isolate);
+#define HT(name, caption, overhead) \
+  name##_ = HistogramTimer(#caption, 0, 10000, 50, isolate, Logger::overhead);
     HISTOGRAM_TIMER_LIST(HT)
 #undef HT
 
@@ -152,7 +152,7 @@ void Counters::ResetHistograms() {
   HISTOGRAM_RANGE_LIST(HR)
 #undef HR
 
-#define HT(name, caption) name##_.Reset();
+#define HT(name, caption, overhead) name##_.Reset();
     HISTOGRAM_TIMER_LIST(HT)
 #undef HT