Unify the server and plugin versions of the generators

pkg/analysis_server/test/domain_completion_util.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 test.domain.completion;
-
 import 'dart:async';
 
-import 'package:analysis_server/plugin/protocol/protocol.dart';
+import 'package:analysis_server/protocol/protocol.dart';
+import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/domain_completion.dart';
 import 'package:analysis_server/src/provisional/completion/dart/completion_dart.dart';
 import 'package:analysis_server/src/services/index/index.dart';
 import 'package:test/test.dart';
 
 import 'analysis_abstract.dart';
 
 class AbstractCompletionDomainTest extends AbstractAnalysisTest {
   String completionId;
@@ skipping 99 matching lines @@
     super.setUp();
     createProject();
     handler = new CompletionDomainHandler(server);
   }
 
   Completer<Null> _getResultsCompleter(String id) {
     return receivedSuggestionsCompleters.putIfAbsent(
         id, () => new Completer<Null>());
   }
 }