UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36

Steps to reproduce the problem:
1. Click the chrome app icon to open chrome and then go to any website
2. Open some other mac application
3. Click the google chrome app icon in the application folder in the dock

What is the expected behavior?
The existing chrome window should be focused

What went wrong?
A new chrome window is created

Did this work before? Yes Unknown.

Chrome version: 63.0.3239.84  Channel: stable
OS Version: OS X 10.13.2
Flash Version: 28.0.0.126

I may have encountered the bug only when upgrading from Elcapitan to high sierra a few months ago.