Operator precedence in isJavaScriptSimpleObject

sdk/lib/html/html_common/conversions_dartium.dart

 part of html_common;
 
 convertDartToNative_PrepareForStructuredClone(value) =>
     new _StructuredCloneDartium().convertDartToNative_PrepareForStructuredClone(value);
 
 convertNativeToDart_AcceptStructuredClone(object, {mustCopy: false}) =>
     new _AcceptStructuredCloneDartium().convertNativeToDart_AcceptStructuredClone(object, mustCopy: mustCopy);
 
 class _StructuredCloneDartium extends _StructuredClone {
   newJsMap() => new js.JsObject(js.context["Object"]);
@@ skipping 26 matching lines @@
 bool isJavaScriptArray(value) => value is js.JsArray;
 
 final _object = js.context["Object"];
 final _getPrototypeOf = _object["getPrototypeOf"];
 _getProto(object) {
   return _getPrototypeOf.apply([object]);
 }
 final _objectProto = js.context["Object"]["prototype"];
 
 bool isJavaScriptSimpleObject(value) {
-  if (!value is js.JsObject) return false;
+  if (value is! js.JsObject) return false;
   var proto = _getProto(value);
   return proto == _objectProto || proto == null;
 }
 bool isImmutableJavaScriptArray(value) =>
     isJavaScriptArray(value) && value["immutable$list"] != null;
 
 final _promiseConstructor = js.context['Promise'];
 bool isJavaScriptPromise(value) => value is js.JsObject && value['constructor'] == _promiseConstructor;
 
 Future convertNativePromiseToDartFuture(js.JsObject promise) {
   var completer = new Completer();
   var newPromise = promise
     .callMethod("then", [(result) => completer.complete(result)])
     .callMethod("catch", [(result) => completer.completeError(result)]);
   return completer.future;
 }