(TBR) Fix test failures

pkg/analysis_server/test/protocol_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.protocol;
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:unittest/matcher.dart';
 import 'package:unittest/unittest.dart';
 
@@ skipping 43 matching lines @@
   }
 }
 
 class ResponseTest {
   static void create_contextDoesNotExist() {
     Response response = new Response.contextDoesNotExist(new Request('0', ''));
     expect(response.id, equals('0'));
     expect(response.error, isNotNull);
     expect(response.toJson(), equals({
       Response.ID: '0',
-      Response.ERROR: 'Context does not exist'
+      Response.ERROR: {'code': -1, 'message': 'Context does not exist'}
     }));
   }
 
   static void create_invalidRequestFormat() {
     Response response = new Response.invalidRequestFormat();
     expect(response.id, equals(''));
     expect(response.error, isNotNull);
     expect(response.toJson(), equals({
       Response.ID: '',
-      Response.ERROR: 'Invalid request'
+      Response.ERROR: {'code': -4, 'message': 'Invalid request'}
     }));
   }
 
   static void create_missingRequiredParameter() {
     Response response = new Response.missingRequiredParameter(new Request('0', ''), 'x');
     expect(response.id, equals('0'));
     expect(response.error, isNotNull);
     expect(response.toJson(), equals({
       Response.ID: '0',
-      Response.ERROR: 'Missing required parameter: x'
+      Response.ERROR: {'code': -5, 'message': 'Missing required parameter: x'}
     }));
   }
 
   static void create_unknownRequest() {
     Response response = new Response.unknownRequest(new Request('0', ''));
     expect(response.id, equals('0'));
     expect(response.error, isNotNull);
     expect(response.toJson(), equals({
       Response.ID: '0',
-      Response.ERROR: 'Unknown request'
+      Response.ERROR: {'code': -7, 'message': 'Unknown request'}
     }));
   }
 
   static void setResult() {
     String resultName = 'name';
     String resultValue = 'value';
     Response response = new Response('0');
     response.setResult(resultName, resultValue);
     expect(response.toJson(), equals({
       Response.ID: '0',
       Response.ERROR: null,
       Response.RESULT: {
         resultName: resultValue
       }
     }));
   }
 }