UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36

Steps to reproduce the problem:
1. Launch Canary in headless mode from a Terminal by running:

cd "/Applications/Google Chrome Canary.app/Contents/MacOS"
./Google\ Chrome\ Canary --disable-gpu --headless --remote-debugging-port=9222 https://www.apple.com

2. In another browser (e.g. regular Chrome), go to "http://localhost:9222".

3. Click on the "Apple" link under the "Inspectable WebContents" heading to open the Headless DevTools interface.

4. In the URL above the screencast, enter in another URL, e.g. "https://www.google.com", and hit enter.

Note that the URL doesn't change.

What is the expected behavior?
With latest Google Chrome (v. 60.0.3112.113) on MacOS, the same steps allow you to navigate to a new URL.

To try it, run:

cd "/Applications/Google Chrome.app/Contents/MacOS"
./Google\ Chrome --disable-gpu --headless --remote-debugging-port=9222 https://www.apple.com

Then open the "Apple" link, and enter in another URL.  Headless Chrome will navigate to the new URL.

What went wrong?
Navigation bar above the Screencast is not allowing you to change the URL anymore.

Did this work before? Yes 60.0.3112.113

Chrome version: 63.0.3216.0  Channel: canary
OS Version: OS X 10.12.6
Flash Version: