Notes: that class should contain background-image attribute and it is merged with igtab_XXRoundedLeftRight.
Image should contain left and right edges and its width should be at least twice large than SizeOfCorners.
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