NSFullSizeContentViewWindowMask

When set, the content view consumes the full size of the window; it can be combined with other window style masks, but is only respected for windows with a title bar. Using this mask opts in to layer backing. Use the Contentlayoutrect or Contentlayoutguide to lay out views underneath the title bar-toolbar area.

static const NSWindowStyleMask NSFullSizeContentViewWindowMask;