"Probably refers to"? That you don't know what "secure" refers to is itself a problem. But more problematic is anyone's defense of Google Chrome's architecture while overlooking that that architecture is implemented with secret software which you aren't allowed to vet, alter, or share with others (parts of software freedom).

This proprietary software apparently allowed for sending Google every URL a Chrome user types in (http://www.favbrowser.com/google-chrome-spyware-confirmed/) and making it easy for extensions to spy on Chrome users (https://labs.detectify.com/2015/07/28/how-i-disabled-your-ch...) which many Chrome extensions apparently do, or activating a Chrome user's microphone and sending the captured data to Google (https://www.privateinternetaccess.com/blog/2015/06/google-ch...). Hardly behavior users are likely to call "secure" because such behavior does not look out for the security of its users, but instead securing access to Chrome user's data.