Fix ViewTest#testWindowFocusChanged

Bug 6293331

Change-Id: I36cd1df207bc8ff5981c437717c6e5bfe0b2393c
diff --git a/tests/tests/view/src/android/view/cts/ViewTest.java b/tests/tests/view/src/android/view/cts/ViewTest.java
index db20614..04ccc09 100644
--- a/tests/tests/view/src/android/view/cts/ViewTest.java
+++ b/tests/tests/view/src/android/view/cts/ViewTest.java
@@ -2445,7 +2445,14 @@
     }
 
     public void testWindowFocusChanged() {
-        MockView view = (MockView) mActivity.findViewById(R.id.mock_view);
+        final MockView view = (MockView) mActivity.findViewById(R.id.mock_view);
+
+        new PollingCheck() {
+            protected boolean check() {
+                return view.hasCalledOnWindowFocusChanged();
+            }
+        }.run();
+
         assertTrue(view.hasCalledOnWindowFocusChanged());
         assertTrue(view.hasCalledDispatchWindowFocusChanged());