Check for null prototype in isJavaScriptSimpleObject

sdk/lib/html/html_common/conversions.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.
 
 
 // Conversions for IDBKey.
 //
 // Per http://www.w3.org/TR/IndexedDB/#key-construct
 //
 // "A value is said to be a valid key if it is one of the following types: Array
@@ skipping 374 matching lines @@
     return JS('', '{data: #, height: #, width: #}',
         imageData.data, imageData.height, imageData.width);
   }
   return imageData;
 }
 
 
 bool isJavaScriptDate(value) => JS('bool', '# instanceof Date', value);
 bool isJavaScriptRegExp(value) => JS('bool', '# instanceof RegExp', value);
 bool isJavaScriptArray(value) => JS('bool', '# instanceof Array', value);
-bool isJavaScriptSimpleObject(value) =>
-    JS('bool', 'Object.getPrototypeOf(#) === Object.prototype', value);
+bool isJavaScriptSimpleObject(value) {
+  var proto = JS('', 'Object.getPrototypeOf(#)', value);
+  return JS('bool', '# === Object.prototype', proto) ||
+      JS('bool', '# === null', proto);
+}
 bool isImmutableJavaScriptArray(value) =>
     JS('bool', r'!!(#.immutable$list)', value);
 
 
 
 const String _serializedScriptValue =
     'num|String|bool|'
     'JSExtendableArray|=Object|'
     'Blob|File|NativeByteBuffer|NativeTypedData'
     // TODO(sra): Add Date, RegExp.
     ;
 const annotation_Creates_SerializedScriptValue =
     const Creates(_serializedScriptValue);
 const annotation_Returns_SerializedScriptValue =
     const Returns(_serializedScriptValue);