Bug 920324 - Add spinbutton and slider to simple traversal rule. r=marcoz

accessible/src/jsat/TraversalRules.jsm

@@ -108,6 +108,8 @@ var gSimpleTraversalRoles =
    ROLE_KEY,
    ROLE_HEADER,
    ROLE_HEADING,
+   ROLE_SLIDER,
+   ROLE_SPINBUTTON,
    // Used for traversing in to child OOP frames.
    ROLE_INTERNAL_FRAME];