UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.84 Safari/537.36

Example URL:
http://www.gesteves.com/dpr-test.html

Steps to reproduce the problem:
1. Open this page on a Mac with a retina screen (DPR 2): http://www.gesteves.com/dpr-test.html
2. Note that the page correctly reports the devicePixelRatio as 2
3. Right-click the link on that page (which points to the same page), and open it in a new tab in the background
4. Switch to that new tab

What is the expected behavior?
After switching to the new tab, the page should continue to report a DPR of 2. This is the behavior that both Safari and Firefox exhibit.

What went wrong?
After switching to the new tab, the page reports an incorrect DPR of 1.

Does it occur on multiple sites: Yes

Is it a problem with a plugin? N/A 

Did this work before? N/A 

Does this work in other browsers? Yes 

Chrome version: 51.0.2704.84  Channel: stable
OS Version: OS X 10.11.5
Flash Version: Shockwave Flash 21.0 r0

This also affects images, although it's harder to reproduce (only seems to happen if the image is not in the cache). If the image is served responsively using srcset (with either sizes or 1x/2x variants), when opening the page in a new tab in the background, Chrome will load the image that corresponds to a DPR of 1, so when you switch to that tab on a high DPI screen all the images are blurry.

I've only been able to test this on OS X, so I don't know if this is present in other operating systems.
 

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