Include default parameter values into summary.

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/type.dart';
@@ skipping 590 matching lines @@
       if (type is FunctionType) {
         b.isFunctionTyped = true;
         b.type = serializeTypeRef(type.returnType, parameter);
         b.parameters = type.parameters
             .map((parameter) => serializeParam(parameter, context))
             .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);
+      }
+    }
     return b;
   }
 
   /**
    * Serialize the given [prefix] into an index into the references table.
    */
   int serializePrefix(PrefixElement element) {
     return referenceMap.putIfAbsent(element, () {
       assert(unlinkedReferences.length == linkedReferences.length);
       int index = unlinkedReferences.length;
@@ skipping 533 matching lines @@
       exportNames.add(new LinkedExportNameBuilder(
           name: name,
           dependency: serializeDependency(dependentLibrary),
           unit: unit,
           kind: kind));
     }
     pb.exportNames = exportNames;
     return pb;
   }
 }