AppBarButtonStyle is used to style a Button (or ToggleButton) for use in an App Bar. Content will be centered and should ...

        AppBarButtonStyle is used to style a Button (or ToggleButton) for use in an App Bar.  Content will be centered 
        and should fit within the 40 pixel radius glyph provided.  16-point Segoe UI Symbol is used for content text 
        to simplify the use of glyphs from that font.  AutomationProperties.Name is used for the text below the glyph.