How to get "Application Shortcut" functionality on Chrome for Mac, as of June 2018:

1. Type chrome://flags/ in the URL bar and hit return
2. Enable these options:
- The new bookmark app system
- Allow hosted apps to be opened in windows
- Creation of app shims for hosted apps on Mac
3. Restart the browser
4. Visit the web page you would like to turn into an application
5. Navigate to Settings > More Tools > Create Shortcut...
6. Give the app a name, make sure "Open as window" is enabled, and click Create
7. The folder Chrome Apps should open in finder. Drag the new app shortcut to the dock or another location for easy access

That's it! You can even quit the app (Cmd-Q) without closing other Chrome windows, as it acts like a separate Mac app.