AutoCAD 360 allows you to create, upload and open PDF/DWG files, but calibrating or scaling a whole drawing is not supported yet.
The app only allows you to scale objects withing the drawing (if that's a DWG file)...Also, you can change a drawing's units, but just for display purposes (
http://help.autocad360.com/customer/portal/articles/1280233-how-do-i-change-the-measuring-units-of-my-drawing-).
When you export your drawings as PDFs, you can define the plotted file's scale as well, through the plot settings.
Best Regards,