Bug 1093312 - Make the disclosure button's focus ring look better. r=mstange.

widget/cocoa/nsNativeThemeCocoa.mm

@@ -3094,6 +3094,8 @@ nsNativeThemeCocoa::GetWidgetOverflow(nsDeviceContext* aContext, nsIFrame* aFram
   int32_t p2a = aFrame->PresContext()->AppUnitsPerDevPixel();
   switch (aWidgetType) {
     case NS_THEME_BUTTON:
+    case NS_THEME_MAC_DISCLOSURE_BUTTON_OPEN:
+    case NS_THEME_MAC_DISCLOSURE_BUTTON_CLOSED:
     case NS_THEME_MOZ_MAC_HELP_BUTTON:
     case NS_THEME_TOOLBAR_BUTTON:
     case NS_THEME_NUMBER_INPUT: