Chrome Version       : 49.0.2623.95
OS Version: 7834.60.0
URLs (if applicable) :
Other browsers tested:
Chrome on all other platforms

What steps will reproduce the problem?
Ex: https://jsfiddle.net/xemcy91t/ (look at the console log)

var win = window.open('about:blank', '', 'height=200,width=300');
console.log(300, 200);
window.setTimeout(function() {
  console.log(win.document.body.clientWidth, win.document.body.clientHeight);
}, 1000);


What is the expected result?
The new window should have clientWidth/clientHeight of 300, 200.

What happens instead of that?
300, 166

It's always 34px smaller than requested. Not sure if that value is dependent on some device property, font sizes, etc.

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

UserAgentString: Mozilla/5.0 (X11; CrOS x86_64 7834.60.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.95 Safari/537.36