Do not delete DOMStringMap and DOMStringList types from idl database.

lib/dom/src/native_DOMImplementation.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.
 
 class Utils {
   static List convertToList(List list) {
     // FIXME: [possible optimization]: do not copy the array if Dart_IsArray is fine w/ it.
     final length = list.length;
     List result = new List(length);
     result.copyFrom(list, 0, 0, length);
@@ skipping 61 matching lines @@
   // Fields.
   void set href(String) native "Location_href_Setter";
 
   // Implementation support.
   static LocationCrossFrameImplementation _createLocationCrossFrameImplementation() => new LocationCrossFrameImplementation._createLocationCrossFrameImplementation();
   LocationCrossFrameImplementation._createLocationCrossFrameImplementation();
 
   String get typeName() => "Location";
 }
 
-class DOMStringMapImplementation extends DOMWrapperBase implements Map<String, String> {
+class DOMStringMapImplementation extends DOMWrapperBase implements DOMStringMap {
   static DOMStringMapImplementation _createDOMStringMapImplementation() => new DOMStringMapImplementation._createDOMStringMapImplementation();
   DOMStringMapImplementation._createDOMStringMapImplementation();
 
   bool containsValue(String value) => Maps.containsValue(this, value);
   bool containsKey(String key) native "DOMStringMap_containsKey_Callback";
   String operator [](String key) native "DOMStringMap_item_Callback";
   void operator []=(String key, String value) native "DOMStringMap_setItem_Callback";
   String putIfAbsent(String key, String ifAbsent()) => Maps.putIfAbsent(this, key, ifAbsent);
   String remove(String key) native "DOMStringMap_remove_Callback";
   void clear() => Maps.clear(this);
   void forEach(void f(String key, String value)) => Maps.forEach(this, f);
   Collection<String> getKeys() native "DOMStringMap_getKeys_Callback";
   Collection<String> getValues() => Maps.getValues(this);
   int get length() => Maps.length(this);
   bool isEmpty() => Maps.isEmpty(this);
 }
+
+class DOMStringListImplementation extends DOMWrapperBase implements DOMStringList {
+  static DOMStringListImplementation _createDOMStringListImplementation() => new DOMStringListImplementation._createDOMStringListImplementation();
+  DOMStringListImplementation._createDOMStringListImplementation();
+
+  // FIXME: provide implementation.
+}