Make isEmpty a getter.

lib/html/scripts/idlparser.dart

 // Copyright (c) 2011, 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.
 
 // IDL grammar variants.
 const int WEBIDL_SYNTAX = 0;
 const int WEBKIT_SYNTAX = 1;
 const int FREMONTCUT_SYNTAX = 2;
 
 /**
@@ skipping 159 matching lines @@
     for (var element in associationList) {
       var name = element[0];
       var value = element[1];
       map[name] = value;
     }
   }
 
   bool has(String key) => map.containsKey(key);
 
   formatMap() {
-    if (map.isEmpty())
+    if (map.isEmpty)
       return '';
     StringBuffer sb = new StringBuffer();
     map.forEach((k, v) {
         sb.add(' $k');
         if (v != null) {
           sb.add('=$v');
         }
       });
     return sb.toString();
   }
@@ skipping 349 matching lines @@
         OR([MANY(CHAR(' \t\r\n')),
             ['//', MANY0([NOT(CHAR('\r\n')), CHAR()])],
             ['#', MANY0([NOT(CHAR('\r\n')), CHAR()])],
             ['/*', MANY0([NOT('*/'), CHAR()]), '*/']]);
 
     // Top level - at least one definition.
     return MANY(Definition);
 
   }
 }