I just sold my MBP in anticipation of the new release so I can't help you with file paths and such.I'm not sure what I did to have my bookmarks gone. One thing I did do is run the Disk Utility. My Dashboard was reset to the default, my bookmarks and history are all gone.
I've checked all of the Library paths mentioned, and there are no bookmark files.
I'm not sure about syncing Chrome with my Gmail account.