UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/604.5.6 (KHTML, like Gecko) Version/11.0.3 Safari/604.5.6

Example URL:
with any URL

Steps to reproduce the problem:
1. Open any website. google.com for example
2. Launch Devtools (option+command+I)
3a. If the Device Toolbar is Off - Just turn it on
3b. If the Device Toolbar is On - Turn it off and again turn in on

What is the expected behavior?
The content covers all the device canvas

What went wrong?
The layout shows the correct size of the selected device, but the content only covers the 1/DPR portion of each width and length

For example, Galaxy S5 has a 360x640 size with DPR = 3
So only 120x240 pixels show content, the rest of the canvas remains blank

More on this ...
a- If you reload the page nothing changes
b- If you change the url, to facebook.com for example, the layout gets rendered successfully 
c- Being in a correct layout, if you change the device, the issue returns

Does it occur on multiple sites: Yes

Is it a problem with a plugin? No 

Did this work before? Yes chrome_64.0.3282.140

Does this work in other browsers? Yes

Chrome version: 	65.0.3325.146  Channel: stable
OS Version: OS X 10.13.3
Flash Version: 

This is affecting automated testing since the chromedriver can not overrun this problem
Two more comments on chromedriver stuff
- Any device configured in Chromedriver can be configured with device pixel ratio, so this problem will disappear if DPR is configured with 1, but other problems related to media management will appear
- When launching chromedriver with mobileEmulation, the device toolbar toggle is off. Is it the expected status?
 

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