Chrome Version       : 65.0.3325.106
OS Version: OS X 10.13.3
URLs (if applicable) : https://unb.ca (or any other website)

The mobile device emulation screen only seems to show the upper left corner of the screen. 
This seems to happen only when the browser window is on an external 1x display connected to a MacBook 

What steps will reproduce the problem?
1. Move browser window to the external 1x display, open website, 
2. Open DevTools and toggle device emulation, everything should render properly 
3. Change the device from existing to a 2x or greater device, eg Pixel 2 or iPhone X 


What is the expected result?
I'd expect to see the page fill the entire screen. 

What happens instead of that?
Only the upper left corner is now rendering, and the rest of the page is white. If you then move the browser window to the laptop screen, more of the window will render (see attached "on-1x-display.png" and "on-2x-display.png") (all if it's a 2x device, or more if it's a 2+x device)

Please provide any additional information below. Attach a screenshot if
possible.

UserAgentString: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.106 Safari/537.36



 

Deleted: on-1x-display.png 226 KB

	on-1x-display.png 226 KB View Download

Deleted: on-2x-display.png 1.3 MB

	on-2x-display.png 1.3 MB View Download