Track live instance and allocation counts for classes

runtime/vm/pages.cc

Index: runtime/vm/pages.cc
diff --git a/runtime/vm/pages.cc b/runtime/vm/pages.cc
index 06f15b31e3c6951d9f4ea5532f14ce8aa61cced1..d5fc8ecaad7c3744c2865a17bd6db6ff3867083a 100644
--- a/runtime/vm/pages.cc
+++ b/runtime/vm/pages.cc
@@ -131,7 +131,9 @@ PageSpace::PageSpace(Heap* heap, intptr_t max_capacity_in_words)
       sweeping_(false),
       page_space_controller_(FLAG_heap_growth_space_ratio,
                              FLAG_heap_growth_rate,
-                             FLAG_heap_growth_time_ratio) {
+                             FLAG_heap_growth_time_ratio),
+      gc_time_micros_(0),
+      collections_(0) {
 }
 
 
@@ -391,6 +393,19 @@ void PageSpace::WriteProtect(bool read_only) {
 }
 
 
+void PageSpace::PrintToJSONObject(JSONObject* object) {
+  JSONObject space(object, "old");
+  space.AddProperty("type", "PageSpace");
+  space.AddProperty("id", "heaps/old");
+  space.AddProperty("name", "PageSpace");
+  space.AddProperty("user_name", "old");
+  space.AddProperty("collections", collections());
+  space.AddProperty("used", UsedInWords() * kWordSize);
+  space.AddProperty("capacity", CapacityInWords() * kWordSize);
+  space.AddProperty("time", RoundMicrosecondsToSeconds(gc_time_micros()));
+}
+
+
 bool PageSpace::ShouldCollectCode() {
   // Try to collect code if enough time has passed since the last attempt.
   const int64_t start = OS::GetCurrentTimeMicros();