UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36

Steps to reproduce the problem:
1. Configure Windows to use 150% scaling.
2. Configure Chrome to use 200% scaling.
3. window.open( 'test.html', new Date().getTime(), 'width=600, height=300' );

What is the expected behavior?
The resulting window window should have 
  window.innerWidth == 600 && window.innerHeight == 300

https://drafts.csswg.org/cssom-view/#the-features-argument-to-the-open()-method

What went wrong?
window.open measures width and height in "windows pixels" instead of CSS pixels.

If the window contains a image with 600px x 300px it will not fit.

First test:
  window.open( 'test.html', new Date().getTime(), 'width=600, height=300' );

Windows Chrome Result (innerWidth x innerHeight)
 100%    100%    600 x 300 (correct)
 100%    200%    400 x 200 (incorrect)
 150%    100%    602 x 302 (almost correct)
 150%    200%    301 x 151 (incorrect)

The problem can be shifted:

window.open( 'test.html', new Date().getTime(), 'width=' + ( 600 * devicePixelRatio ) + ', height=' + ( 300 * devicePixelRatio ) );

Windows Chrome Result (innerWidth x innerHeight)
 100%    100%    600 x 300 (correct)
 100%    200%    600 x 300 (correct)
 150%    100%    902 x 452 (incorrect)
 150%    200%    901 x 451 (incorrect)

So the solution can either handle windows scaling or chrome scaling but not both.

Did this work before? N/A 

Chrome version: 61.0.3163.100  Channel: n/a
OS Version: 10.0
Flash Version: 

If there was a way to detect the scale factor of chrome or windows independently, the problem would be easy to solve.
However I only found devicePixelRatio which gives the product of windows and chrome scaling (i.e. 3.0 if windows is at 150% and chrome is at 200%).
 

Deleted: test.html 407 bytes

test.html 407 bytes View Download