Make server use the common protocol classes

pkg/analysis_server/test/integration/edit/organize_directives_test.dart

 // Copyright (c) 2017, 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_generated.dart';
+import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../support/integration_tests.dart';
 
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(OrganizeDirectivesTest);
   });
 }
@@ skipping 50 matching lines @@
     writeFile(pathname, text);
     standardAnalysisSetup();
 
     try {
       await sendEditOrganizeDirectives(pathname);
     } on ServerErrorMessage catch (message) {
       expect(message.error['code'], 'ORGANIZE_DIRECTIVES_ERROR');
     }
   }
 }