pkg/matcher: a few more strong-mode fixes

test/test_utils.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.
 
-import 'dart:collection';
-
 import 'package:test/test.dart';
 
 void shouldFail(value, Matcher matcher, expected) {
   var failed = false;
   try {
     expect(value, matcher);
   } on TestFailure catch (err) {
     failed = true;
 
     var _errorString = err.message;
@@ skipping 19 matching lines @@
 
 class Widget {
   int price;
 }
 
 class HasPrice extends CustomMatcher {
   HasPrice(matcher) : super("Widget with a price that is", "price", matcher);
   featureValueOf(actual) => actual.price;
 }
 
-class SimpleIterable extends IterableBase<int> {
+class SimpleIterable extends Iterable<int> {
   final int count;
 
   SimpleIterable(this.count);
 
-  bool contains(int val) => count < val ? false : true;
-
-  bool any(bool f(element)) {
-    for (var i = 0; i <= count; i++) {
-      if (f(i)) return true;
-    }
-    return false;
-  }
-
-  String toString() => "<[$count]>";
-
-  Iterator get iterator {
-    return new _SimpleIterator(count);
-  }
+  Iterator<int> get iterator => new _SimpleIterator(count);
 }
 
 class _SimpleIterator implements Iterator<int> {
   int _count;
   int _current;
 
   _SimpleIterator(this._count);
 
   bool moveNext() {
     if (_count > 0) {
       _current = _count;
       _count--;
       return true;
     }
     _current = null;
     return false;
   }
 
   int get current => _current;
 }