It's synced to the Google servers, but the hashes are within the settings file itself. I'm unsure if the code is public, though, as it is not part of Chromium.

It's synced to the Google servers, but the hashes are within the settings file itself. I'm unsure if the code is public, though, as it is not part of Chromium. The downside is that an unaware user that prefers not to sync their stuff to Google and fastidiously backs up all their user settings in Windows is going to lose everything they have stored in Chrome except their bookmarks and passwords if their computer dies or they try to move to a new one.