Make server use the common protocol classes

pkg/analysis_server/test/services/refactoring/extract_local_test.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.
 
 import 'dart:async';
 import 'dart:convert';
 
-import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analysis_server/src/services/correction/status.dart';
 import 'package:analysis_server/src/services/refactoring/extract_local.dart';
 import 'package:analysis_server/src/services/refactoring/refactoring.dart';
+import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'abstract_refactoring.dart';
 
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(ExtractLocalTest);
   });
 }
@@ skipping 1315 matching lines @@
   List<String> _getCoveringExpressions() {
     List<String> subExpressions = <String>[];
     for (int i = 0; i < refactoring.coveringExpressionOffsets.length; i++) {
       int offset = refactoring.coveringExpressionOffsets[i];
       int length = refactoring.coveringExpressionLengths[i];
       subExpressions.add(testCode.substring(offset, offset + length));
     }
     return subExpressions;
   }
 }