Use TracedValue in runtime statistics.

src/counters.cc

Index: src/counters.cc
diff --git a/src/counters.cc b/src/counters.cc
index df75e212791d1743001334ae4047e761d6d62f18..8fcfd541411d433911bf2003d4ce46d8535ff873 100644
--- a/src/counters.cc
+++ b/src/counters.cc
@@ -277,9 +277,11 @@ void RuntimeCallCounter::Reset() {
   time = base::TimeDelta();
 }
 
-void RuntimeCallCounter::Dump(std::stringstream& out) {
-  out << "\"" << name << "\":[" << count << "," << time.InMicroseconds()
-      << "],";
+void RuntimeCallCounter::Dump(v8::tracing::TracedValue* value) {
+  value->BeginArray(name);
+  value->AppendLongInteger(count);
+  value->AppendLongInteger(time.InMicroseconds());
+  value->EndArray();
 }
 
 // static
@@ -365,37 +367,33 @@ void RuntimeCallStats::Reset() {
   in_use_ = true;
 }
 
-std::string RuntimeCallStats::Dump() {
-  buffer_.str(std::string());
-  buffer_.clear();
-  buffer_ << "{";
+void RuntimeCallStats::Dump(v8::tracing::TracedValue* value) {
 #define DUMP_COUNTER(name) \
-  if (this->name.count > 0) this->name.Dump(buffer_);
+  if (this->name.count > 0) this->name.Dump(value);
   FOR_EACH_MANUAL_COUNTER(DUMP_COUNTER)
 #undef DUMP_COUNTER
 
 #define DUMP_COUNTER(name, nargs, result_size) \
-  if (this->Runtime_##name.count > 0) this->Runtime_##name.Dump(buffer_);
+  if (this->Runtime_##name.count > 0) this->Runtime_##name.Dump(value);
   FOR_EACH_INTRINSIC(DUMP_COUNTER)
 #undef DUMP_COUNTER
 
 #define DUMP_COUNTER(name) \
-  if (this->Builtin_##name.count > 0) this->Builtin_##name.Dump(buffer_);
+  if (this->Builtin_##name.count > 0) this->Builtin_##name.Dump(value);
   BUILTIN_LIST_C(DUMP_COUNTER)
 #undef DUMP_COUNTER
 
 #define DUMP_COUNTER(name) \
-  if (this->API_##name.count > 0) this->API_##name.Dump(buffer_);
+  if (this->API_##name.count > 0) this->API_##name.Dump(value);
   FOR_EACH_API_COUNTER(DUMP_COUNTER)
 #undef DUMP_COUNTER
 
 #define DUMP_COUNTER(name) \
-  if (this->Handler_##name.count > 0) this->Handler_##name.Dump(buffer_);
+  if (this->Handler_##name.count > 0) this->Handler_##name.Dump(value);
   FOR_EACH_HANDLER_COUNTER(DUMP_COUNTER)
 #undef DUMP_COUNTER
-  buffer_ << "\"END\":[]}";
+
   in_use_ = false;
-  return buffer_.str();
 }
 
 }  // namespace internal