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

pkg/analysis_server/test/abstract_context.dart

Index: pkg/analysis_server/test/abstract_context.dart
diff --git a/pkg/analysis_server/test/abstract_context.dart b/pkg/analysis_server/test/abstract_context.dart
index e3c4b93508e4d74bdf0e32d153e602c63efb2595..e139528d04391925c257d771aa1c52ee2607c732 100644
--- a/pkg/analysis_server/test/abstract_context.dart
+++ b/pkg/analysis_server/test/abstract_context.dart
@@ -76,6 +76,20 @@ class AbstractContextTest {
    */
   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);