Revert "Remove Expect from core library."

tests/compiler/dart2js/parser_helper.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 parser_helper;
 
-import "package:expect/expect.dart";
 import "dart:uri";
 
 import "../../../sdk/lib/_internal/compiler/implementation/elements/elements.dart";
 import "../../../sdk/lib/_internal/compiler/implementation/tree/tree.dart";
 import "../../../sdk/lib/_internal/compiler/implementation/scanner/scannerlib.dart";
 import "../../../sdk/lib/_internal/compiler/implementation/source_file.dart";
 import "../../../sdk/lib/_internal/compiler/implementation/util/util.dart";
 
 import "../../../sdk/lib/_internal/compiler/implementation/elements/modelx.dart"
     show CompilationUnitElementX,
@@ skipping 77 matching lines @@
   return parseBodyCode(source, (parser, tokens) => parser.parseUnit(tokens),
                        diagnosticHandler: diagnosticHandler);
 }
 
 // TODO(ahe): We define this method to avoid having to import
 // the scanner in the tests. We should move SourceString to another
 // location instead.
 SourceString buildSourceString(String name) {
   return new SourceString(name);
 }