Remove Registry from registerMetadataConstant

pkg/compiler/lib/src/constants/values.dart

 // 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.
 
 library dart2js.constants.values;
 
 import '../common.dart';
 import '../core_types.dart';
 import '../dart_types.dart';
 import '../elements/elements.dart'
@@ skipping 733 matching lines @@
   get hashCode => (referenced.hashCode * 17 + prefix.hashCode) & 0x3fffffff;
 
   List<ConstantValue> getDependencies() => <ConstantValue>[referenced];
 
   accept(ConstantValueVisitor visitor, arg) => visitor.visitDeferred(this, arg);
 
   DartType getType(CoreTypes types) => referenced.getType(types);
 
   String toDartText() => 'deferred(${referenced.toDartText()})';
 
-  String toStructuredText() => 'DeferredConstant($referenced)';
+  String toStructuredText() {
+    return 'DeferredConstant(${referenced.toStructuredText()})';
+  }
 }
 
 /// A constant value resulting from a non constant or erroneous constant
 /// expression.
 // TODO(johnniwinther): Expand this to contain the error kind.
 class NonConstantValue extends ConstantValue {
   bool get isConstant => false;
 
   @override
   accept(ConstantValueVisitor visitor, arg) {
     // TODO(johnniwinther): Should this be part of the visiting?
   }
 
   @override
   List<ConstantValue> getDependencies() => const <ConstantValue>[];
 
   @override
   DartType getType(CoreTypes types) => const DynamicType();
 
   @override
   String toStructuredText() => 'NonConstant';
 
   @override
   String toDartText() => '>>non-constant<<';
 }