Revert "JSInvocationMirror - return unmodifiable list or map"

sdk/lib/_internal/compiler/js_lib/constant_map.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.
 
 part of _js_helper;
 
 class ConstantMapView<K, V> extends UnmodifiableMapView
                       implements ConstantMap {
-  ConstantMapView(Map base) : super(base);
+ ConstantMapView(Map base) : super(base);
 }
 
 abstract class ConstantMap<K, V> implements Map<K, V> {
   // Used to create unmodifiable maps from other maps.
   factory ConstantMap.from(Map other) {
     List keys = other.keys.toList();
     bool allStrings = true;
     for (var k in keys) {
       if (k is! String) {
         allStrings = false;
@@ skipping 159 matching lines @@
   Iterable<K> get keys {
     return _getMap().keys;
   }
 
   Iterable<V> get values {
     return _getMap().values;
   }
 
   int get length => _getMap().length;
 }