Request for comments on overall approach.

runtime/vm/snapshot.h

 // Copyright (c) 2012, 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_SNAPSHOT_H_
 #define VM_SNAPSHOT_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/bitfield.h"
@@ skipping 487 matching lines @@
   void WriteObject(RawObject* raw);
 
   void WriteClassId(RawClass* cls);
 
   // Unmark all objects that were marked as forwarded for serializing.
   void UnmarkAll();
 
   // Writes a full snapshot of the Isolate.
   void WriteFullSnapshot();
 
+  uword GetObjectTags(RawObject* raw);
+
  private:
   class ForwardObjectNode : public ZoneAllocated {
    public:
-    ForwardObjectNode(RawObject* raw, RawClass* cls) : raw_(raw), cls_(cls) {}
+    ForwardObjectNode(RawObject* raw, uword tags) : raw_(raw), tags_(tags) {}
     RawObject* raw() const { return raw_; }
-    RawClass* cls() const { return cls_; }
+    uword tags() const { return tags_; }
 
    private:
     RawObject* raw_;
-    RawClass* cls_;
+    uword tags_;
 
     DISALLOW_COPY_AND_ASSIGN(ForwardObjectNode);
   };
 
   intptr_t MarkObject(RawObject* raw, RawClass* cls);
 
   void WriteInlinedObject(RawObject* raw);
 
   ObjectStore* object_store() const { return object_store_; }
 
@@ skipping 32 matching lines @@
 
  private:
   SnapshotWriter* writer_;
 
   DISALLOW_COPY_AND_ASSIGN(SnapshotWriterVisitor);
 };
 
 }  // namespace dart
 
 #endif  // VM_SNAPSHOT_H_