UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.101 Safari/537.36

Steps to reproduce the problem:
1. In a terminal, start Chromium in headless mode on a fixed port (e.g, 9222):  /Applications/Chromium.app/Contents/MacOS/Chromium --headless --disable-gpu --remote-debugging-port=9222
2. In another terminal connect to the launched headless chromium via chrome-remote-interface: ./node_modules/.bin/chrome-remote-interface -p 9222 inspect
3. Try executing one of the documented DevTools Protocol methods of Browser domain:
a. Browser.getWindowForTarget()
b. Browser.getWindowBounds()
c. Browser.setWindowBounds()

What is the expected behavior?
I expect to have some indication that abovementioned methods exist/are implemented. Since for sake of brevity I have omitted the arguments in these method calls, I expect to have some "Invalid parameters" error.

What went wrong?
For every Browser domain method call, I get the "wasn't found" error:

>>> Browser.getWindowForTarget()
{ error:
   { code: -32601,
     message: '\'Browser.getWindowForTarget\' wasn\'t found' } }
>>> Browser.getWindowBounds()
{ error:
   { code: -32601,
     message: '\'Browser.getWindowBounds\' wasn\'t found' } }
>>> Browser.setWindowBounds()
{ error:
   { code: -32601,
     message: '\'Browser.setWindowBounds\' wasn\'t found' } }

That makes me think that these methods have not been implemented and that disagrees with the DevTools documentation (link above)

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: 60.0.3112.101  Channel: canary
OS Version: OS X 10.12.6
Flash Version: