Add summary support for ParameterElement.defaultValueCode.

pkg/analyzer/lib/src/summary/summarize_elements.dart

 // Copyright (c) 2015, 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 serialization.elements;
 
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/member.dart';
@@ skipping 730 matching lines @@
             .toList();
       } else {
         b.type = serializeTypeRef(type, context);
       }
     }
     if (parameter is ConstVariableElement) {
       ConstVariableElement constParameter = parameter as ConstVariableElement;
       Expression initializer = constParameter.constantInitializer;
       if (initializer != null) {
         b.defaultValue = serializeConstExpr(initializer);
+        b.defaultValueCode = parameter.defaultValueCode;
       }
     }
     // TODO(scheglov) VariableMember.initializer is not implemented
     if (parameter is! VariableMember && parameter.initializer != null) {
       b.initializer = serializeExecutable(parameter.initializer);
     }
     {
       SourceRange visibleRange = parameter.visibleRange;
       if (visibleRange != null) {
         b.visibleOffset = visibleRange.offset;
@@ skipping 666 matching lines @@
       exportNames.add(new LinkedExportNameBuilder(
           name: name,
           dependency: serializeDependency(dependentLibrary),
           unit: unit,
           kind: kind));
     }
     pb.exportNames = exportNames;
     return pb;
   }
 }