Make server use the common protocol classes

pkg/analysis_server/test/analysis/get_errors_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.
 
-library test.analysis.get_errors;
-
 import 'dart:async';
 
 import 'package:analysis_server/protocol/protocol.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analysis_server/src/domain_analysis.dart';
+import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../analysis_abstract.dart';
 
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(GetErrorsTest);
   });
 }
@@ skipping 123 matching lines @@
   Request _createGetErrorsRequest(String file) {
     return new AnalysisGetErrorsParams(file).toRequest(requestId);
   }
 
   Future<List<AnalysisError>> _getErrors(String file) async {
     Request request = _createGetErrorsRequest(file);
     Response response = await serverChannel.sendRequest(request);
     return new AnalysisGetErrorsResult.fromResponse(response).errors;
   }
 }