Fix logging test

lib/runtime/dart_logging_runtime.dart

 // Copyright (c) 2015, 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 dev_compiler.runtime.dart_logging_runtime;
 
 import 'dart:mirrors' as mirrors;
 
 import 'dart_runtime.dart' as rt;
 export 'dart_runtime.dart' show Arity, getArity, type;
@@ skipping 31 matching lines @@
 }
 
 CastRecord _lookupInCache(Type runtimeType, Type staticType) {
   var subcache = _cache[runtimeType];
   if (subcache == null) return null;
   return subcache[staticType];
 }
 
 var _successCache = <Type, Set<Type>>{};
 
-dynamic cast(dynamic obj, Type fromType, Type staticType, String kind,
-    String key, bool dartIs, bool isGround) {
+dynamic cast(dynamic obj, Type fromType, Type staticType, [String kind,
+    String key, bool dartIs, bool isGround]) {
   var runtimeType = obj.runtimeType;
   // Short-circuit uninteresting cases.
   if (_skipSuccess && _successCache.containsKey(staticType)) {
     if (_successCache[staticType].contains(runtimeType)) {
       return obj;
     }
   }
 
   if (key == null) {
     // If no key is past in, use the caller's frame as a key.
@@ skipping 92 matching lines @@
       category('failure', failure);
       category('mismatch', mismatch);
       category('error', error);
     }
   });
   if (clear) {
     _recordMap.clear();
   }
   return buffer.toString();
 }