I can not find them under ~/Library/Application Support/Google/Chrome/; Where are they?
This question is related to
macos
google-chrome
google-chrome-extension
You can find all Chrome extensions in below location.
/Users/{mac_user}/Library/Application Support/Google/Chrome/Default/Extensions
For Mac EI caption/Mac Sierra, Chrome extension folders were located at
/Users/$USER/Library/Application\ Support/Google/Chrome/Profile*/Extensions/
With the new App Launcher YOUR APPS (not chrome extensions) stored in Users/[yourusername]/Applications/Chrome Apps/
They are found on either one of the below locations depending on how chrome was installed
~/Users/<username>/Library/Application\ Support/Google/Chrome/Default/Extensions
/Library/Application\ Support/Google/Chrome/Default/Extensions
Source: Stackoverflow.com