Make RefactoringProblem.location optional.

pkg/analysis_server/test/integration/protocol_matchers.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.
 //
 // This file has been automatically generated.  Please do not edit it manually.
 // To regenerate the file, use the script
 // "pkg/analysis_server/spec/generate_files".
 
 /**
  * Matchers for data types defined in the analysis server API
@@ skipping 1553 matching lines @@
   "POSITIONAL",
   "NAMED"
 ]);
 
 /**
  * RefactoringProblem
  *
  * {
  *   "severity": RefactoringProblemSeverity
  *   "message": String
- *   "location": Location
+ *   "location": optional Location
  * }
  */
 final Matcher isRefactoringProblem = new LazyMatcher(() => new MatchesJsonObject(
   "RefactoringProblem", {
     "severity": isRefactoringProblemSeverity,
-    "message": isString,
+    "message": isString
+  }, optionalFields: {
     "location": isLocation
   }));
 
 /**
  * RefactoringProblemSeverity
  *
  * enum {
  *   INFO
  *   WARNING
  *   ERROR
@@ skipping 301 matching lines @@
  *
  * {
  *   "newName": String
  * }
  */
 final Matcher isRenameOptions = new LazyMatcher(() => new MatchesJsonObject(
   "rename options", {
     "newName": isString
   }));