Roll Observatory deps (charted -> ^0.3.0)

packages/csslib/lib/src/validate.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 csslib.src.validate;
 
 import 'package:csslib/visitor.dart';
 import 'package:source_span/source_span.dart';
 
 /** Can be thrown on any Css runtime problem includes source location. */
@@ skipping 35 matching lines @@
     } else {
       String error = selector.simpleSelector.toString();
       throw new CssSelectorException(
           'Selectors can not have combinators (>, +, or ~) before $error');
     }
   }
 
   // Validate the @{css expression} only .class and #elementId are valid inside
   // of @{...}.
   static template(List<Selector> selectors) {
-    var errorSelector; // signal which selector didn't match.
     bool found = false; // signal if a selector is matched.
     int matches = 0; // < 0 IdSelectors, > 0 ClassSelector
 
     // At most one selector group (any number of simple selector sequences).
     assert(selectors.length <= 1);
 
     for (final sels in selectors) {
       for (final selector in sels.simpleSelectorSequences) {
         found = false;
         var simpleSelector = selector.simpleSelector;
@@ skipping 49 matching lines @@
         }
       }
     }
 
     // Every selector must match.
     Selector selector = selectors[0];
     assert((matches >= 0 ? matches : -matches) ==
         selector.simpleSelectorSequences.length);
   }
 }