- More use of pre-allocated read-only handles.

runtime/lib/mirrors.cc

 // 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.
 
 #include "lib/invocation_mirror.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart_entry.h"
 #include "vm/exceptions.h"
 #include "vm/object_store.h"
@@ skipping 241 matching lines @@
                                          const Instance& owner_mirror) {
   const MirrorReference& field_ref =
       MirrorReference::Handle(MirrorReference::New(field));
 
   const String& name = String::Handle(field.UserVisibleName());
 
   const Array& args = Array::Handle(Array::New(6));
   args.SetAt(0, field_ref);
   args.SetAt(1, name);
   args.SetAt(2, owner_mirror);
-  args.SetAt(3, Instance::Handle());  // Null for type.
+  args.SetAt(3, Object::null_instance());  // Null for type.
   args.SetAt(4, Bool::Get(field.is_static()));
   args.SetAt(5, Bool::Get(field.is_final()));
 
   return CreateMirror(Symbols::_LocalVariableMirrorImpl(), args);
 }
 
 static RawFunction* CallMethod(const Class& cls) {
   if (cls.IsSignatureClass()) {
     return cls.signature_function();
   }
@@ skipping 1133 matching lines @@
 }
 
 
 DEFINE_NATIVE_ENTRY(VariableMirror_type, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   const Field& field = Field::Handle(ref.GetFieldReferent());
   return field.type();
 }
 
 }  // namespace dart