Notes: that class is merged with igtab_XXRoundedForHolderScrollInner and it is used only when orientation of tabs is left or right.
It allows to shift tabs vertically and it should contain only the top style attribute.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2