- Add an isolate field to visitors.

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 552 matching lines @@
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ScriptSnapshotWriter);
 };
 
 
 // An object pointer visitor implementation which writes out
 // objects to a snap shot.
 class SnapshotWriterVisitor : public ObjectPointerVisitor {
  public:
-  explicit SnapshotWriterVisitor(SnapshotWriter* writer) : writer_(writer) {}
+  explicit SnapshotWriterVisitor(SnapshotWriter* writer)
+      : ObjectPointerVisitor(Isolate::Current()), writer_(writer) {}
 
   virtual void VisitPointers(RawObject** first, RawObject** last);
 
  private:
   SnapshotWriter* writer_;
 
   DISALLOW_COPY_AND_ASSIGN(SnapshotWriterVisitor);
 };
 
 }  // namespace dart
 
 #endif  // VM_SNAPSHOT_H_