Add "checked mode compile time error" type to analysis server API.

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/tool/spec/generate_files".
 
 /**
  * Matchers for data types defined in the analysis server API
@@ skipping 849 matching lines @@
   "INFO",
   "WARNING",
   "ERROR"
 ]);
 
 /**
  * AnalysisErrorType
  *
  * enum {
  *   ANGULAR
+ *   CHECKED_MODE_COMPILE_TIME_ERROR
  *   COMPILE_TIME_ERROR
  *   HINT
  *   POLYMER
  *   STATIC_TYPE_WARNING
  *   STATIC_WARNING
  *   SYNTACTIC_ERROR
  *   TODO
  * }
  */
 final Matcher isAnalysisErrorType = new MatchesEnum("AnalysisErrorType", [
   "ANGULAR",
+  "CHECKED_MODE_COMPILE_TIME_ERROR",
   "COMPILE_TIME_ERROR",
   "HINT",
   "POLYMER",
   "STATIC_TYPE_WARNING",
   "STATIC_WARNING",
   "SYNTACTIC_ERROR",
   "TODO"
 ]);
 
 /**
@@ skipping 1141 matching lines @@
  *
  * {
  *   "newName": String
  * }
  */
 final Matcher isRenameOptions = new LazyMatcher(() => new MatchesJsonObject(
   "rename options", {
     "newName": isString
   }));