pkg/matcher: Reverting 36881,36896 while investigating dart2js checked crash

pkg/matcher/lib/src/map_matchers.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.map_matchers;
+part of matcher;
 
-import 'expect.dart';
-import 'interfaces.dart';
-
-/// Returns a matcher which matches maps containing the given [value].
+/**
+ * Returns a matcher which matches maps containing the given [value].
+ */
 Matcher containsValue(value) => new _ContainsValue(value);
 
 class _ContainsValue extends Matcher {
   final _value;
 
   const _ContainsValue(this._value);
 
   bool matches(item, Map matchState) => item.containsValue(_value);
   Description describe(Description description) =>
       description.add('contains value ').addDescriptionOf(_value);
 }
 
-/// Returns a matcher which matches maps containing the key-value pair
-/// with [key] => [value].
+/**
+ * Returns a matcher which matches maps containing the key-value pair
+ * with [key] => [value].
+ */
 Matcher containsPair(key, value) =>
     new _ContainsMapping(key, wrapMatcher(value));
 
 class _ContainsMapping extends Matcher {
   final _key;
   final Matcher _valueMatcher;
 
   const _ContainsMapping(this._key, Matcher this._valueMatcher);
 
   bool matches(item, Map matchState) =>
@@ skipping 12 matching lines @@
           .addDescriptionOf(_key);
     } else {
       mismatchDescription.add(' contains key ').addDescriptionOf(_key).
           add(' but with value ');
       _valueMatcher.describeMismatch(item[_key], mismatchDescription,
           matchState, verbose);
       return mismatchDescription;
     }
   }
 }