The function was moved to QtDeclarative

It is about default behavior for QQuickWindow, when there is no any
activeFocusItem in the whole window, Tab/BackTab key could help you
to focus the item in the tab focus chain.

Change-Id: Iccd770794e2f99a9a74c3a11f0ed278264a02d9e
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>

src/controls/ApplicationWindow.qml

@@ -125,14 +125,6 @@ Window {
     /*! \internal */
     default property alias data: contentArea.data
 
-    /*! \internal */
-    Binding {
-        target: contentItem
-        property: "activeFocusOnTab"
-        when: activeFocusItem
-        value: activeFocusItem ? ( (activeFocusItem != contentItem) ? !activeFocusItem.activeFocusOnTab : true ) : false
-    }
-
     color: syspal.window
 
     SystemPalette {id: syspal}