Update charted to 0.4.8 and roll

packages/unittest/lib/src/matcher/operator_matchers.dart

 // Copyright (c) 2012, 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 unittest.matcher.operator_matchers;
 
 import 'interfaces.dart';
 import 'util.dart';
 
 /// This returns a matcher that inverts [matcher] to its logical negation.
@@ skipping 73 matching lines @@
       }
     }
     return false;
   }
 
   Description describe(Description description) =>
       description.addAll('(', ' or ', ')', _matchers);
 }
 
 List<Matcher> _wrapArgs(arg0, arg1, arg2, arg3, arg4, arg5, arg6) {
-  Iterable<Matcher> matchers;
+  Iterable args;
   if (arg0 is List) {
     if (arg1 != null ||
         arg2 != null ||
         arg3 != null ||
         arg4 != null ||
         arg5 != null ||
         arg6 != null) {
       throw new ArgumentError('If arg0 is a List, all other arguments must be'
           ' null.');
     }
 
-    matchers = arg0;
+    args = arg0;
   } else {
-    matchers =
-        [arg0, arg1, arg2, arg3, arg4, arg5, arg6].where((e) => e != null);
+    args = [arg0, arg1, arg2, arg3, arg4, arg5, arg6].where((e) => e != null);
   }
 
-  return matchers.map((e) => wrapMatcher(e)).toList();
+  return args.map((e) => wrapMatcher(e)).toList();
 }