isJavaScriptPromise needs to handle Promise not being defined (IE)

sdk/lib/html/html_common/conversions_dart2js.dart

 part of html_common;
 
 /// Converts a JavaScript object with properties into a Dart Map.
 /// Not suitable for nested objects.
 Map convertNativeToDart_Dictionary(object) {
   if (object == null) return null;
   var dict = {};
   var keys = JS('JSExtendableArray', 'Object.getOwnPropertyNames(#)', object);
   for (final key in keys) {
     dict[key] = JS('var', '#[#]', object, key);
@@ skipping 63 matching lines @@
 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) {
   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);
-bool isJavaScriptPromise(value) => JS('bool', r'# instanceof Promise', value);
+bool isJavaScriptPromise(value) =>
+    JS('bool', r'typeof Promise != "undefined" && # instanceof Promise', value);
 
 Future convertNativePromiseToDartFuture(promise) {
   var completer = new Completer();
   var then = convertDartClosureToJS((result) => completer.complete(result), 1);
   var error = convertDartClosureToJS((result) => completer.completeError(result), 1);
   var newPromise = JS('', '#.then(#).catch(#)', promise, then, error);
   return completer.future;
 }