Move minitest.dart into the expect package.

pkg/dev_compiler/test/codegen/lib/html/js_typed_interop_test.dart

 // Copyright (c) 2015, 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.
 
 @JS()
 library js_typed_interop_test;
 
 import 'dart:html';
 
 import 'package:js/js.dart';
-import 'package:minitest/minitest.dart';
+import 'package:expect/minitest.dart';
 
 _injectJs() {
   document.body.append(new ScriptElement()
     ..type = 'text/javascript'
     ..innerHtml = r"""
   var Foo = {
     multiplyDefault2: function(a, b) {
       if (arguments.length >= 2) return a *b;
       return a * 2;
     }
@@ skipping 393 matching lines @@
   group('html', () {
     test('return html type', () {
       expect(getCanvasContext() is CanvasRenderingContext2D, isTrue);
     });
     test('js path contains html types', () {
       expect(propertyOnWindow, equals(42));
       expect(propertyOnDocument, equals(45));
     });
   });
 }