Add a use counter API

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index a4b311f6ecacd7d4b4a760931475bf4d9405c2ec..0210f19d4f51728431f81639da067f6edfe76a3d 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -2343,6 +2343,18 @@ void Isolate::RunMicrotasks() {
 }
 
 
+void Isolate::SetUseCounterCallback(v8::Isolate::UseCounterCallback callback) {
+  ASSERT(!use_counter_callback_);
+  use_counter_callback_ = callback;
+}
+
+
+void Isolate::CountUsage(v8::Isolate::UseCounterFeature feature) {
+  if (use_counter_callback_)

[Sven Panne, 2014/06/23 09:29:39]

Following the good example of the Heartbleed bug here? :-)

+    use_counter_callback_(reinterpret_cast<v8::Isolate*>(this), feature);
+}
+
+
 bool StackLimitCheck::JsHasOverflowed() const {
   StackGuard* stack_guard = isolate_->stack_guard();
 #ifdef USE_SIMULATOR