Add requestTime to responses

pkg/analyzer_plugin/lib/src/protocol/protocol_internal.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 'dart:collection';
 import 'dart:convert' hide JsonDecoder;
 
 import 'package:analyzer_plugin/protocol/protocol.dart';
 import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:analyzer_plugin/protocol/protocol_generated.dart';
@@ skipping 499 matching lines @@
     return new Exception('Missing key $key at $jsonPath');
   }
 }
 
 /**
  * The result data associated with a response.
  */
 abstract class ResponseResult implements HasToJson {
   /**
    * Return a response whose result data is this object for the request with the
-   * given [id].
+   * given [id], where the request was received at the given [requestTime].
    */
-  Response toResponse(String id);
+  Response toResponse(String id, int requestTime);
 }