Usually under the profile path.

You can find your profile path by typing: chrome://version in the url bar, and search for Profile Path.

The path is usually: /Users/%username%/Library/Application Support/Google/Chrome/Default/ (alternatively ~/Library/Application Support/Google/Chrome/Default/ if you are logged in under the account you want to explore)

If you have a chrome user profile other than the default one, replace Default with that profile name.

Look at directories "Local Storage" and "Local Extension Settings" under that path.

Gmail Offline usually stores its files under your profile path.

You can find your profile path by typing chrome://version in the address bar, and searching for Profile Path.

The path is usually:

/Users/%username%/Library/Application Support/Google/Chrome/Default/

Alternatively, if you are logged in under the account you want to explore, the path is:

~/Library/Application Support/Google/Chrome/Default/

If you have a Chrome user profile other than the default one, replace Default with that profile name.

You should then look at the "Local Storage" and "Local Extension Settings" directories under that path.