Implement a heap profiler for the Dart managed heap.

runtime/vm/scavenger.cc

Index: runtime/vm/scavenger.cc
diff --git a/runtime/vm/scavenger.cc b/runtime/vm/scavenger.cc
index 2410da2ff5e846b124a92f539ffa6b88541a5909..a867fad5f22dfbd4f889823e823a9a096e78ea31 100644
--- a/runtime/vm/scavenger.cc
+++ b/runtime/vm/scavenger.cc
@@ -344,6 +344,16 @@ void Scavenger::VisitObjectPointers(ObjectPointerVisitor* visitor) const {
 }
 
 
+void Scavenger::VisitObjects(ObjectVisitor* visitor) const {
+  uword cur = FirstObjectStart();
+  while (cur < top_) {
+    RawObject* raw_obj = RawObject::FromAddr(cur);
+    visitor->VisitObject(raw_obj);
+    cur += raw_obj->Size();
+  }
+}
+
+
 void Scavenger::Scavenge() {
   // TODO(cshapiro): Add a decision procedure for determining when the
   // the API callbacks should be invoked.