Google dev tools window causing high CPU usage on macbook pro

[George Dimov]

Hello , 

My Google Chrome Dev tools ( webpage doesn't matter ) are causing High CPU usage when they are opened. 

What I've tried :

 - removing all addons
 - resetting profile, default settings both browser and dev tools 

 - reinstalling the OSX and the Chrome Browser

 - tried under newer OSX ( sierra and high sierra ) 

When I check the Task Manager - the tab with opened dev tools is under 200% CPU usage. 

I need to monitor somehow what is causing the problem but I don't have the knowledge to do that. 

Please give me some advice.

Machine: Macbook pro 15 inch late 2015 

Processor : 2.2 GHz Intel Core i7

Mac Os X:  El Capitan 10.11.6  Google Chrome 67.0.3396.99

Thanks.