UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36

Steps to reproduce the problem:
1. Install Chrome on the Mac.
2. Disable PDF viewer in Chrome (optional).
3. Set Adobe Acrobat Reader DC as PDF viewer in "Info" setting on a file.
4. Wait a day.
5. Chrome makes itself the PDF viewer.

What is the expected behavior?
Once Adobe Acrobat Reader DC or any other program is set as the PDF viewer by the user, Chrome continues to respect that settings and does not make itself the PDF viewer.

What went wrong?
Chrome made itself the PDF viewer when I told it not to. This caused other bugs ( https://bugs.chromium.org/p/chromium/issues/detail?id=334474#c33 ) but even as those bugs seem to be fixed, the problem remains that Chrome sets itself to be the PDF viewer. 

I work with PDF files and need to use the standard PDF viewer tools. If I open a PDF with a nonstandard application like Preview or Chrome, I end up making mistakes because other programs do not support all Adobe features. So I do not ever want Chrome to open PDF files, ever, for any purpose. That's why I disabled the PDF viewer in Chrome. I don't see why it is making itself the PDF viewer.

Did this work before? Yes Don't know. Has been going on for a while.

Chrome version: 57.0.2987.133  Channel: stable
OS Version: OS X 10.12.3
Flash Version: