Safer interface for heap iteration.

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index 195623b9b709483661e9a2fd91af3d2fdf544612..50df955d613eb4b7d7baccc77390012d4184bae5 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -1426,12 +1426,6 @@ void Isolate::Shutdown() {
   ASSERT(top_resource() == NULL);
 #if defined(DEBUG)
   if (heap_ != NULL) {
-    // Wait for concurrent GC tasks to finish before final verification.
-    PageSpace* old_space = heap_->old_space();
-    MonitorLocker ml(old_space->tasks_lock());
-    while (old_space->tasks() > 0) {
-      ml.Wait();
-    }
     // The VM isolate keeps all objects marked.
     heap_->Verify(this == Dart::vm_isolate() ? kRequireMarked : kForbidMarked);
   }
@@ -1513,6 +1507,14 @@ Monitor* Isolate::isolates_list_monitor_ = NULL;
 Isolate* Isolate::isolates_list_head_ = NULL;
 
 
+void Isolate::IterateObjectPointers(ObjectPointerVisitor* visitor,
+                                    bool visit_prologue_weak_handles,
+                                    bool validate_frames) {
+  HeapIterationScope heap_iteration_scope;
+  VisitObjectPointers(visitor, visit_prologue_weak_handles, validate_frames);
+}
+
+
 void Isolate::VisitObjectPointers(ObjectPointerVisitor* visitor,
                                   bool visit_prologue_weak_handles,
                                   bool validate_frames) {