Make server use the common protocol classes

pkg/analysis_server/test/analysis/notification_analysis_options_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.
 
 import 'package:analysis_server/protocol/protocol.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart'
     hide AnalysisOptions;
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/domain_analysis.dart';
 import 'package:analyzer/src/generated/engine.dart';
+import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:linter/src/rules.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../analysis_abstract.dart';
 import '../mocks.dart';
 
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(NewAnalysisOptionsFileNotificationTest);
@@ skipping 314 matching lines @@
   @override
   String get optionsFilePath => '$projectPath/analysis_options.yaml';
 }
 
 @reflectiveTest
 class OldAnalysisOptionsFileNotificationTest
     extends AnalysisOptionsFileNotificationTest {
   @override
   String get optionsFilePath => '$projectPath/.analysis_options';
 }