This ensures that overridden wxComboBox::Clear() is called even when it's invoked via a pointer or a reference to wxItemContainer (and not just one to wxComboBox itself or its other base wxTextEntry). Closes #16654. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@78082 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775