Re-apply "Remove unittest and matcher from the repo."

pkg/matcher/test/test_common.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 matcher.test_common;
-
-import 'dart:collection';
-
-import 'package:matcher/matcher.dart';
-
-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> {
-  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);
-  }
-}
-
-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;
-}
-