Review Changes

Author: gspencergoog

lib/ui/platform_dispatcher.dart

@@ -1319,6 +1319,10 @@ class Locale {
   /// [region](https://github.com/unicode-org/cldr/blob/master/common/validity/region.xml) for
   /// each of languageCode, scriptCode and countryCode respectively.
   ///
+  /// The [languageCode] subtag is optional. When there is no language subtag,
+  /// the parameter should be omitted or set to "und". When not supplied, the
+  /// [languageCode] defaults to "und", an undefined language code.
+  ///
   /// The [countryCode] subtag is optional. When there is no country subtag,
   /// the parameter should be omitted or passed `null` instead of an empty-string.
   ///

testing/dart/window_hooks_integration_test.dart

@@ -428,7 +428,7 @@ void main() {
   });
 
   test('PlatformDispatcher.locale returns unknown locale when locales is set to empty list', () {
-    Locale? locale;
+    late Locale locale;
     runZoned(() {
       window.onLocaleChanged = () {
         locale = PlatformDispatcher.instance.locale;
@@ -437,5 +437,6 @@ void main() {
 
     _updateLocales(<String>[]);
     expectEquals(locale, const Locale.fromSubtags());
+    expectEquals(locale.languageCode, 'und');
   });
 }