UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.95 Safari/537.36

Steps to reproduce the problem:
1. Install any extension, that extends DevTools with new panel
2. Go to google.com and open DevTools
3. Undock DevTools into separate window
4. Open an extension's custom panel
5. Open devtools for this panel and go to console
6. Try to execute "chrome.runtime.openOptionsPage()"

What is the expected behavior?
Options page for this extension will be opened

What went wrong?
> "Uncaught TypeError: chrome.runtime.openOptionsPage is not a function"

Did this work before? Yes 

Does this work in other browsers? N/A

Chrome version: 55.0.2883.95  Channel: stable
OS Version: OS X 10.12.2
Flash Version: Shockwave Flash 24.0 r0

I am working on some chrome devtools extension, and noticed that method "openOptionsPage" is not defined anymore. 
I don't know exactly which update affected it, but it worked few days ago. 

It also reproduces on Windows 10 @ Chrome 55.0.2883.87