Issue 22157. Cancel a pending refactoring request on receiving a new one.

pkg/analysis_server/lib/src/protocol.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 protocol;
 
 import 'dart:collection';
 import 'dart:convert';
 
 part 'generated_protocol.dart';
@@ skipping 792 matching lines @@
    */
   Response.sortMembersInvalidFile(Request request)
       : this(
           request.id,
           error: new RequestError(
               RequestErrorCode.SORT_MEMBERS_INVALID_FILE,
               'Error during `edit.sortMembers`: invalid file.'));
 
   /**
    * Initialize a newly created instance to represent the
+   * REFACTORING_REQUEST_CANCELLED error condition.
+   */
+  Response.refactoringRequestCancelled(Request request)
+      : this(
+          request.id,
+          error: new RequestError(
+              RequestErrorCode.REFACTORING_REQUEST_CANCELLED,
+              'The `edit.getRefactoring` request was cancelled.'));
+
+  /**
+   * Initialize a newly created instance to represent the
    * SORT_MEMBERS_PARSE_ERRORS error condition.
    */
   Response.sortMembersParseErrors(Request request, int numErrors)
       : this(
           request.id,
           error: new RequestError(
               RequestErrorCode.SORT_MEMBERS_PARSE_ERRORS,
               'Error during `edit.sortMembers`: file has $numErrors scan/parse errors.'));
 
   /**
@@ skipping 76 matching lines @@
     hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3));
     hash = hash ^ (hash >> 11);
     return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
   }
 
   static int hash2(a, b) => finish(combine(combine(0, a), b));
 
   static int hash4(a, b, c, d) =>
       finish(combine(combine(combine(combine(0, a), b), c), d));
 }