1. Provide a framework to traverse persistent prolog weak handles.

runtime/vm/isolate.h

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_ISOLATE_H_
 #define VM_ISOLATE_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/thread.h"
@@ skipping 95 matching lines @@
   void RegisterClass(const Class& cls);
   void RegisterClassAt(intptr_t index, const Class& cls);
   void ValidateClassTable();
 
   // Visit all object pointers.
   void VisitObjectPointers(ObjectPointerVisitor* visitor,
                            bool visit_prologue_weak_persistent_handles,
                            bool validate_frames);
 
   // Visits weak object pointers.
-  void VisitWeakPersistentHandles(HandleVisitor* visit,
+  void VisitWeakPersistentHandles(HandleVisitor* visitor,
                                   bool visit_prologue_weak_persistent_handles);
+  void VisitPrologueWeakPersistentHandles(HandleVisitor* visitor);
 
   StoreBuffer* store_buffer() { return &store_buffer_; }
   static intptr_t store_buffer_offset() {
     return OFFSET_OF(Isolate, store_buffer_);
   }
 
   ClassTable* class_table() { return &class_table_; }
   static intptr_t class_table_offset() {
     return OFFSET_OF(Isolate, class_table_);
   }
@@ skipping 539 matching lines @@
   char* script_url_;
   char* library_url_;
   char* class_name_;
   char* function_name_;
   char* exception_callback_name_;
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_