This class requires wxTaskBarButton to be really implemented, so there is no need to even define the MSW-specific version of it if wxUSE_TASKBARBUTTON is 0 anyhow. This fixes a compilation problem with wxUSE_TASKBARBUTTON==0 but, more importantly, just makes more sense. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77745 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775