8233565: [TESTBUG] NullModalityDialogTest.java fails on MacOS

Reviewed-by: phh
Backport-of: 2b5869a

Author: caojoshua

test/jdk/ProblemList.txt

@@ -482,7 +482,6 @@ java/awt/Modal/ModalFocusTransferTests/FocusTransferDialogsDocModalTest.java 816
 java/awt/GraphicsDevice/DisplayModes/CycleDMImage.java 7099223 linux-all,solaris-all,windows-all
 java/awt/Window/WindowResizing/DoubleClickTitleBarTest.java 8233557 macosx-all
 java/awt/Window/WindowOwnedByEmbeddedFrameTest/WindowOwnedByEmbeddedFrameTest.java 8233558 macosx-all
-java/awt/Modal/NullModalityDialogTest/NullModalityDialogTest.java 8233565 macosx-all
 java/awt/keyboard/AllKeyCode/AllKeyCode.java 8242930 macosx-all
 java/awt/FullScreen/8013581/bug8013581.java 8169471 macosx-all
 java/awt/event/MouseEvent/RobotLWTest/RobotLWTest.java 8233568 macosx-all

test/jdk/java/awt/Modal/NullModalityDialogTest/NullModalityDialogTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2007, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2007, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -82,7 +82,8 @@ public void doOpenAction() {
     NullModalityDialogTest() throws Exception {
 
         robot = new ExtendedRobot();
-        EventQueue.invokeLater(this::createGUI);
+        robot.setAutoDelay(100);
+        EventQueue.invokeAndWait(this::createGUI);
     }
 
     private void createGUI() {
@@ -133,7 +134,9 @@ public void doTest() throws Exception {
 
         dialog.openGained.reset();
 
-        robot.type(KeyEvent.VK_TAB);
+        robot.keyPress(KeyEvent.VK_TAB);
+        robot.keyRelease(KeyEvent.VK_TAB);
+        robot.waitForIdle();
 
         dialog.openGained.waitForFlagTriggered();
         assertTrue(dialog.openGained.flag(),