extract LocalConstructorContributor from local reference contributor

pkg/analysis_server/lib/src/provisional/completion/dart/completion_plugin.dart

Index: pkg/analysis_server/lib/src/provisional/completion/dart/completion_plugin.dart
diff --git a/pkg/analysis_server/lib/src/provisional/completion/dart/completion_plugin.dart b/pkg/analysis_server/lib/src/provisional/completion/dart/completion_plugin.dart
index 7b6d62c7fccc71c1043fc18acab8e87f60acf296..b29063500bb3ae56ee3191965f21ce3367b893e4 100644
--- a/pkg/analysis_server/lib/src/provisional/completion/dart/completion_plugin.dart
+++ b/pkg/analysis_server/lib/src/provisional/completion/dart/completion_plugin.dart
@@ -15,6 +15,7 @@ import 'package:analysis_server/src/services/completion/dart/keyword_contributor
 import 'package:analysis_server/src/services/completion/dart/label_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/library_member_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/library_prefix_contributor.dart';
+import 'package:analysis_server/src/services/completion/dart/local_constructor_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/named_constructor_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/static_member_contributor.dart';
 import 'package:analysis_server/src/services/completion/dart/type_member_contributor.dart';
@@ -89,6 +90,8 @@ class DartCompletionPlugin implements Plugin {
     registerExtension(DART_COMPLETION_CONTRIBUTOR_EXTENSION_POINT_ID,
         () => new LibraryPrefixContributor());
     registerExtension(DART_COMPLETION_CONTRIBUTOR_EXTENSION_POINT_ID,
+        () => new LocalConstructorContributor());
+    registerExtension(DART_COMPLETION_CONTRIBUTOR_EXTENSION_POINT_ID,
         () => new NamedConstructorContributor());
     registerExtension(DART_COMPLETION_CONTRIBUTOR_EXTENSION_POINT_ID,
         () => new StaticMemberContributor());