Default arg support continued (flutter-intellij#553).

pkg/analysis_server/test/abstract_context.dart

 // Copyright (c) 2014, 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 testing.abstract_context;
 
 import 'dart:async';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 58 matching lines @@
       return _driver;
     }
     throw new StateError('Should be used with the new analysis driver.');
   }
 
   /**
    * Return `true` if the new analysis driver should be used by these tests.
    */
   bool get enableNewAnalysisDriver => false;
 
+  Source addMetaPackageSource() => addPackageSource(
+      'meta',
+      'meta.dart',
+      r'''
+library meta;
+
+const Required required = const Required();
+
+class Required {
+  final String reason;
+  const Required([this.reason]);
+}
+''');
+
   Source addPackageSource(String packageName, String filePath, String content) {
     packageMap[packageName] = [(newFolder('/pubcache/$packageName'))];
     File file = newFile('/pubcache/$packageName/$filePath', content);
     return file.createSource();
   }
 
   Source addSource(String path, String content, [Uri uri]) {
     File file = newFile(path, content);
     if (enableNewAnalysisDriver) {
       driver.addFile(path);
@@ skipping 113 matching lines @@
  * [engine.GeneralizingElementVisitor].
  */
 class _ElementVisitorFunctionWrapper extends GeneralizingElementVisitor {
   final _ElementVisitorFunction function;
   _ElementVisitorFunctionWrapper(this.function);
   visitElement(Element element) {
     function(element);
     super.visitElement(element);
   }
 }