Track live instance and allocation counts for classes

runtime/vm/heap.cc

Index: runtime/vm/heap.cc
diff --git a/runtime/vm/heap.cc b/runtime/vm/heap.cc
index 63d0c9d75758c49981b45c49dd23f1813fd5e43c..1d2f5c04d10ca76bc576350e17efa19cbebd051f 100644
--- a/runtime/vm/heap.cc
+++ b/runtime/vm/heap.cc
@@ -173,6 +173,7 @@ void Heap::CollectGarbage(Space space, ApiCallbacks api_callbacks) {
     case kCode: {
       bool promotion_failure = new_space_->HadPromotionFailure();
       RecordBeforeGC(kOld, promotion_failure ? kPromotionFailure : kOldSpace);
+      UpdateClassStats();
       old_space_->MarkSweep(invoke_api_callbacks);
       RecordAfterGC();
       PrintStats();
@@ -192,6 +193,13 @@ void Heap::UpdateObjectHistogram() {
 }
 
 
+void Heap::UpdateClassStats() {
+  Isolate* isolate = Isolate::Current();
+  ClassTable* class_table = isolate->class_table();
+  class_table->ResetCounters();
+}
+
+
 void Heap::CollectGarbage(Space space) {
   ApiCallbacks api_callbacks;
   if (space == kOld) {
@@ -205,6 +213,7 @@ void Heap::CollectGarbage(Space space) {
 
 void Heap::CollectAllGarbage() {
   RecordBeforeGC(kNew, kFull);
+  UpdateClassStats();
   new_space_->Scavenge(kInvokeApiCallbacks);
   RecordAfterGC();
   PrintStats();