8224830: test/jdk/java/awt/Focus/ModalExcludedWindowClickTest/ModalExcludedWindowClickTest.java fails on linux-x64

Reviewed-by: jdv
diff --git a/test/jdk/java/awt/Focus/ModalExcludedWindowClickTest/ModalExcludedWindowClickTest.java b/test/jdk/java/awt/Focus/ModalExcludedWindowClickTest/ModalExcludedWindowClickTest.java
index cf27234..91fac11 100644
--- a/test/jdk/java/awt/Focus/ModalExcludedWindowClickTest/ModalExcludedWindowClickTest.java
+++ b/test/jdk/java/awt/Focus/ModalExcludedWindowClickTest/ModalExcludedWindowClickTest.java
@@ -117,7 +117,9 @@
         } else {
             robot.mouseMove(p.x + (int)(d.getWidth()/2), p.y + (int)(d.getHeight()/2));
         }
+        waitForIdle();
         robot.mousePress(InputEvent.BUTTON1_MASK);
+        robot.delay(50);
         robot.mouseRelease(InputEvent.BUTTON1_MASK);
         waitForIdle();
     }
@@ -125,8 +127,9 @@
         while (true) {
             try {
                 Thread.sleep(100);
-                c.getLocationOnScreen();
-                break;
+                Point p = c.getLocationOnScreen();
+                if (p != null)
+                    break;
             } catch (InterruptedException e) {
                 throw new RuntimeException(e);
             } catch (IllegalComponentStateException e) {}