Provide API support for weak handles and post-mortem finalization.

runtime/vm/scavenger.h

 // Copyright (c) 2011, 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_SCAVENGER_H_
 #define VM_SCAVENGER_H_
 
 #include "vm/assert.h"
 #include "vm/flags.h"
 #include "vm/globals.h"
@@ skipping 57 matching lines @@
   static intptr_t end_offset() { return OFFSET_OF(Scavenger, end_); }
 
   intptr_t in_use() const { return (top_ - FirstObjectStart()); }
 
   void VisitObjectPointers(ObjectPointerVisitor* visitor) const;
 
  private:
   uword FirstObjectStart() const { return to_->start() | object_alignment_; }
   void Prologue();
   void IterateRoots(Isolate* isolate, ObjectPointerVisitor* visitor);
-  void IterateWeakRoots(Isolate* isolate, ObjectPointerVisitor* visitor);
+  void IterateWeakRoots(Isolate* isolate, HandleVisitor* visitor);
   void ProcessToSpace(ObjectPointerVisitor* visitor);
   void Epilogue();
 
   // During a scavenge we need to remember the promoted objects.
   // This is implemented as a stack of objects at the end of the to space. As
   // object sizes are always greater than sizeof(uword) and promoted objects do
   // not consume space in the to space they leave enough room for this stack.
   void PushToPromotedStack(uword addr) {
     end_ -= sizeof(addr);
     ASSERT(end_ > top_);
@@ skipping 35 matching lines @@
 
   friend class ScavengerVisitor;
   friend class ScavengerWeakVisitor;
 
   DISALLOW_COPY_AND_ASSIGN(Scavenger);
 };
 
 }  // namespace dart
 
 #endif  // VM_SCAVENGER_H_