Disable Chrome PDF Viewer
Modern versions of Google’s Chrome have a built-in viewer for displaying files encoded in the ubiquitous PDF file format. This means that when you click on a link to a PDF file, it will automatically open in the web browser.
While this is fine for most end users, it can be an annoying behavior for others. For example, I often need to modify PDF files before uploading them to web services like Evernote, and having to wait for a file to first display in the browser, then download it to my computer for modification, only to have to re-upload to Evernote is a pain.
If this is something you go through too often and you wish Chrome treated these files differently, there is a way to modify this behavior.
In order to prevent Chrome from displaying PDF files in the browser, you will need to disable the Chrome PDF Viewer. To accomplish this, type the following into the Chrome address bar:
Scroll down until you see the Chrome PDF Viewer option and select the Disable link. Now, when you click on a link to a PDF file in your browser, it will automatically be downloaded to your computer.
Source Online Tech Tips