Add check for top level widget leaks in kernel test of QtWidgets.

Add a cleanup function for the check and disable animations
in tst_qwidgetaction to prevent effect widgets from interfering
(vista style animations).

Change-Id: I043ecb131c8dcd07b6ef10bc75c9e010ab569e85
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@theqtcompany.com>

tests/auto/widgets/kernel/qactiongroup/tst_qactiongroup.cpp

@@ -42,6 +42,7 @@ class tst_QActionGroup : public QObject
     Q_OBJECT
 
 private slots:
+    void cleanup() { QVERIFY(QApplication::topLevelWidgets().isEmpty()); }
     void enabledPropagation();
     void visiblePropagation();
     void exclusive();

tests/auto/widgets/kernel/qdesktopwidget/tst_qdesktopwidget.cpp

@@ -73,6 +73,7 @@ void tst_QDesktopWidget::init()
 
 void tst_QDesktopWidget::cleanup()
 {
+    QVERIFY(QApplication::topLevelWidgets().isEmpty());
 }
 
 void tst_QDesktopWidget::numScreens()

tests/auto/widgets/kernel/qlayout/tst_qlayout.cpp

@@ -66,6 +66,7 @@ public:
     virtual ~tst_QLayout();
 
 private slots:
+    void cleanup() { QVERIFY(QApplication::topLevelWidgets().isEmpty()); }
     void getSetCheck();
     void geometry();
     void smartMaxSize();

tests/auto/widgets/kernel/qshortcut/tst_qshortcut.cpp

@@ -108,6 +108,7 @@ public slots:
 public slots:
     void initTestCase();
     void cleanupTestCase();
+    void cleanup() { QCOMPARE(QApplication::topLevelWidgets().size(), 1); }
 
 private slots:
     void number_data();

tests/auto/widgets/kernel/qsizepolicy/tst_qsizepolicy.cpp

@@ -44,6 +44,7 @@ class tst_QSizePolicy : public QObject
     Q_OBJECT
 
 private Q_SLOTS:
+    void cleanup() { QVERIFY(QApplication::topLevelWidgets().isEmpty()); }
     void qtest();
     void defaultValues();
     void getSetCheck_data() { data(); }

tests/auto/widgets/kernel/qwidgetaction/tst_qwidgetaction.cpp

@@ -55,6 +55,8 @@ class tst_QWidgetAction : public QObject
 {
     Q_OBJECT
 private slots:
+    void initTestCase();
+    void cleanup();
     void defaultWidget();
     void visibilityUpdate();
     void customWidget();
@@ -65,6 +67,19 @@ private slots:
     void releaseWidgetCrash();
 };
 
+void tst_QWidgetAction::initTestCase()
+{
+    // Disable menu/combo animations to prevent the alpha widgets from getting in the
+    // way in popup(), failing the top level leak check in cleanup().
+    QApplication::setEffectEnabled(Qt::UI_AnimateMenu, false);
+    QApplication::setEffectEnabled(Qt::UI_AnimateCombo, false);
+}
+
+void tst_QWidgetAction::cleanup()
+{
+    QVERIFY(QApplication::topLevelWidgets().isEmpty());
+}
+
 void tst_QWidgetAction::defaultWidget()
 {
     {