Pass in the isolate parameter to the weak persistent callback handler so that

runtime/vm/handles.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_HANDLES_H_
 #define VM_HANDLES_H_
 
 #include "vm/allocation.h"
 #include "vm/flags.h"
 #include "vm/os.h"
@@ skipping 46 matching lines @@
 
 
 // Forward declarations.
 class ObjectPointerVisitor;
 
 DECLARE_FLAG(bool, verify_handles);
 DECLARE_DEBUG_FLAG(bool, trace_handles);
 
 class HandleVisitor {
  public:
+  explicit HandleVisitor(Isolate* isolate) : isolate_(isolate) {}
+  virtual ~HandleVisitor() {}
+
+  Isolate* isolate() const { return isolate_; }
+
   virtual void VisitHandle(uword addr, bool is_prologue_weak) = 0;
 
-  virtual ~HandleVisitor() {
-  }
+ private:
+  Isolate* isolate_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(HandleVisitor);
 };
 
 
 template <int kHandleSizeInWords, int kHandlesPerChunk, int kOffsetOfRawPtr>
 class Handles {
  public:
   Handles()
       : zone_blocks_(NULL),
         first_scoped_block_(NULL),
         scoped_blocks_(&first_scoped_block_) {
@@ skipping 260 matching lines @@
 };
 #endif  // defined(DEBUG)
 
 // Macro to start a no handles scope in the code.
 #define NOHANDLESCOPE(isolate)                                                 \
     dart::NoHandleScope no_vm_internal_handles_scope_(isolate);
 
 }  // namespace dart
 
 #endif  // VM_HANDLES_H_