Add support for specifying files needing analysis

pkg/analysis_server/test/edit/sort_members_test.dart

Index: pkg/analysis_server/test/edit/sort_members_test.dart
diff --git a/pkg/analysis_server/test/edit/sort_members_test.dart b/pkg/analysis_server/test/edit/sort_members_test.dart
index 18d3052825534cbc9c306479952b93c93e466178..6aa638c72137dc8adbfba8b0e78bc8e5a97189e5 100644
--- a/pkg/analysis_server/test/edit/sort_members_test.dart
+++ b/pkg/analysis_server/test/edit/sort_members_test.dart
@@ -7,7 +7,6 @@ library test.edit.sort_members;
 import 'dart:async';
 
 import 'package:analysis_server/src/edit/edit_domain.dart';
-import 'package:analysis_server/src/plugin/server_plugin.dart';
 import 'package:analysis_server/src/protocol.dart';
 import 'package:plugin/manager.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
@@ -30,9 +29,8 @@ class SortMembersTest extends AbstractAnalysisTest {
     super.setUp();
     createProject();
     ExtensionManager manager = new ExtensionManager();
-    ServerPlugin plugin = new ServerPlugin();
-    manager.processPlugins([plugin]);
-    handler = new EditDomainHandler(server, plugin);
+    manager.processPlugins([server.serverPlugin]);
+    handler = new EditDomainHandler(server);
   }
 
   Future test_BAD_doesNotExist() {