Add support for specifying files needing analysis

pkg/analysis_server/test/edit/format_test.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 test.edit.format;
 
 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';
 import 'package:unittest/unittest.dart' hide ERROR;
 
 import '../analysis_abstract.dart';
 import '../mocks.dart';
 
 main() {
   groupSep = ' | ';
   defineReflectiveTests(FormatTest);
 }
 
 @reflectiveTest
 class FormatTest extends AbstractAnalysisTest {
   @override
   void setUp() {
     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_formatNoOp() {
     // Already formatted source
     addTestFile('''
 main() {
   int x = 3;
 }
 ''');
     return waitForTasksFinished().then((_) {
@@ skipping 55 matching lines @@
     });
   }
 
   EditFormatResult _formatAt(int selectionOffset, int selectionLength) {
     Request request = new EditFormatParams(
         testFile, selectionOffset, selectionLength).toRequest('0');
     Response response = handleSuccessfulRequest(request);
     return new EditFormatResult.fromResponse(response);
   }
 }