Called by the framework when the user invokes the undo command after activating the OLE item in place.
The default implementation calls DeactivateUI to deactivate the server's user interface. Override this function if you are implementing the undo command in your container application. In your override, call the base class version of the function and then undo the last command executed in your application.
For more information, see IOleInPlaceSite::DeactivateAndUndo in the Windows SDK.