How do I set the icon in Developer Tools popup window?

[cagret]

How do I change the icon (it's empty) when showing Developer Tools?
I edited resources/inspector/devtools.html and added:

<link rel="icon" type="image/png" href="favicon.png">
and
<link rel="shortcut icon" href="favicon.ico">

But it didn't work. Changing the path to file:// or other does not make any difference.

I also edited HandleBeforeCreated() and checked whether some of the arguments allow to set the icon, but can't find anything.

Anyone knows how to do it? Thanks.