Add a version of heap snapshots that use only fields and stack frames as roots and only include ins…

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index 7f25aec4a6c6160b27f4bc7a6a6e11a4b98747ee..b14396397f6e77e8bbd3e7e352e8c445199f7704 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -1790,6 +1790,13 @@ void Isolate::IterateObjectPointers(ObjectPointerVisitor* visitor,
 }
 
 
+void Isolate::IterateStackPointers(ObjectPointerVisitor* visitor,
+                                   bool validate_frames) {
+  HeapIterationScope heap_iteration_scope;
+  VisitStackPointers(visitor, validate_frames);
+}
+
+
 void Isolate::VisitObjectPointers(ObjectPointerVisitor* visitor,
                                   bool validate_frames) {
   ASSERT(visitor != NULL);
@@ -1861,6 +1868,12 @@ void Isolate::VisitObjectPointers(ObjectPointerVisitor* visitor,
     deopt_context()->VisitObjectPointers(visitor);
   }
 
+  VisitStackPointers(visitor, validate_frames);
+}
+
+
+void Isolate::VisitStackPointers(ObjectPointerVisitor* visitor,
+                                 bool validate_frames) {
   // Visit objects in all threads (e.g., Dart stack, handles in zones).
   thread_registry()->VisitObjectPointers(visitor, validate_frames);
 }