UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.119 Safari/537.36

Steps to reproduce the problem:

I have found a way pages can 100% escape Developer Tools monitoring.

Works every time.

All the page has to do is have a button that opens a new tab/window.

And then in that new tab/window do whatever it pleases. Totally with no
way for the user to monitor it. It has already done what it wants to do
by the time the user can switch to the new tab/window, turn on Developer
tools, and then reload the page to supposedly see what it did.

Because Developer tools is tab/window based, it can not govern other
tab/windows.

Therefore just like it has a "Preserve Logs" to last through redirects,

it also needs a "Also monitor newly spawned tabs/windows".

The idea would be each newly spawned window, at the bottom etc. would
have their own Developer Tools half window.

Another idea might be an option that would make Developer Tools "on" for
all windows, instead of currently "off".

How to reproduce? Fill out your U.S. tax form on the official IRS
https://www.freefilefillableforms.com/
site. Then hit "print form".
(Be sure to do it while the tax filing season is still open.)

What is the expected behavior?
Can monitor everything going in to the browser.

What went wrong?
Some things you still just can't monitor.

Did this work before? No 

Chrome version: 64.0.3282.119  Channel: n/a
OS Version: 
Flash Version: 

(Mainly one is interested in the Network portion of Developer Tools here.)