How do I download links (to PDFs) with one click in Chrome for Mac OS X?
Go to Chrome settings > Advanced

Click on privacy settings > Content

Scroll down to Plug ins

Click on 


  Disable Individual plug-ins


Disable the 


  Chrome PDF Viewer


That will unfortunately disable it for all PDF preview.

But the good news is

now you have the simple one click on a PDF link and it will offer you to download the PDF file.