Remove use of Expect from test scripts and idlparser_test.

tools/dom/scripts/idlparser_test.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.
 
 library idlparser_test;
 
 import '../../../utils/peg/pegparser.dart';
 
 part 'idlparser.dart';
 part 'idlrenderer.dart';
@@ skipping 77 matching lines @@
   try {
     ast = grammar.parse(rule, input);
   } catch (exception) {
     ast = exception;
   }
 
   var formatted = ast;
   if (expected is String)
     formatted = printList(ast);
 
-  Expect.equals(expected, formatted, "parse: $input");
+  if (expected != formatted) {
+    throw new StateError("parse: $input");
+  }
 }
 
 // Prints the list in [1,2,3] notation, including nested lists.
 void printList(item) {
   if (item is List) {
     StringBuffer sb = new StringBuffer();
     sb.add('[');
     var sep = '';
     for (var x in item) {
       sb.add(sep);
       sb.add(printList(x));
       sep = ',';
     }
     sb.add(']');
     return sb.toString();
   }
   if (item == null)
     return 'null';
   return item.toString();
 }