Well, I've hated the whole trend toward browsers opening PDF files inside themselves, as I always prefer to use a dedicated PDF reader when dealing with PDFs. Whether you use Adobe Reader DC or some other reader, you can follow these instructions to make Chrome not open PDFs itself, but hand them off to the PDF reader you have set in Windows to handle PDF files.
Making the Google Chrome Browser Open PDF Files in Your Chosen PDF Reader
1. Make sure that your chosen PDF Reader is already installed on your computer and that is has been set as the default app for PDF files.
2. Activate the Chrome Menu Button, then choose Settings. ALT+F,S
3. Navigate to the Privacy and Security Pane, then to the Site Settings option in that pane, and activate its button.
4. In the Site Settings Options list, navigate down to the PDF Documents option, and activate its button.
5. In the PDF Documents dialog, throw the toggle for Download PDF files instead of automatically opening them in Chrome to ON.
6. Close Settings.
After having done this, when a link related to a PDF file is activated, the file will download in the background and open in your chosen PDF reader instead of Chrome. For small PDF files this occurs very quickly, but for larger ones it can take a few moments for the download to complete before the file opens.--
Brian - Windows 10 Pro, 64-Bit, Version 1909, Build 18363
Power is being told you're not loved and not being destroyed by it.