- Use NoHandleScope in leaf methods

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"
 
 namespace dart {
@@ skipping 281 matching lines @@
 //   NOHANDLESCOPE(isolate);
 //   ....
 //   .....
 //   critical code that manipulates dart objects directly.
 //   ....
 // }
 #if defined(DEBUG)
 class NoHandleScope : public StackResource {
  public:
   explicit NoHandleScope(BaseIsolate* isolate);
+  NoHandleScope();
   ~NoHandleScope();
 
  private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(NoHandleScope);
+  DISALLOW_COPY_AND_ASSIGN(NoHandleScope);
 };
 #else  // defined(DEBUG)
 class NoHandleScope : public ValueObject {
  public:
   explicit NoHandleScope(BaseIsolate* isolate) { }
+  NoHandleScope() { }
   ~NoHandleScope() { }
 
  private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(NoHandleScope);
+  DISALLOW_COPY_AND_ASSIGN(NoHandleScope);
 };
 #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_