Preview Particular Files for Chrome Extension create

Hi //////////////////////////////// ////////////////////////////////// ....................................... Pleae check all carefully. On looking forward to prevent PDF Files of being downloaded, we need an Google Chrome extension to open a special kind of file (.uni) that can be treated as a PDF file. This kind of files will be downloaded from our website. This extension need to give user the chance to send to print the file, on all users printers but not on those that can match some patterns on their name such as "Adobe PDF", "PDF to File" and so on. We sell on our web site some drawings That people can buy This draws are on an PDF file But our costumers actually are downloading them and they are sharing this files So they are broking our business Thats why our idea is to put a chrome extension To prevent download this files, but allowing them to send to printer We need to keep this solution as confidential so they dont realize that they can download the file, and change the extension of the file to PDF and handle as a common PDF file And we need to block to send to some printers that can save this files as PDF That's it