UserAgent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36

Steps to reproduce the problem:
1. Get excited about --headless on Windows in Chrome 59 by reading: https://news.ycombinator.com/item?id=14101233
2. Install Chrome Canary to get Chrome 59
3. .\chrome.exe --headless --remote-debugging-port=9222 --user-data-dir=.\user-data --disable-gpu --enable-logging --v=9  https://chromium.org
4. notice Chrome Canary window drawn on Windows desktop

What is the expected behavior?
Chrome running as background process

What went wrong?
Windows is drawn on Windows desktop

Did this work before? N/A 

Chrome version: 59.0.3070.0  Channel: canary
OS Version: 10.0
Flash Version: 

I'm ultimately trying to make chrome run in a headless Docker Windows Server container. After trying failing at that for a while, I tried reproducing on Windows 10.
 

Deleted: chrome-windows.png 29.7 KB

	chrome-windows.png 29.7 KB View Download