OMG, I deleted a bookmark/folder in Chromium! How can I get it back?
Calm down! Take a deep breath, open a terminal window and run:
cd ~/.config/chromium/Default && mv Bookmarks Bookmarks.old && mv Bookmarks.bak Bookmarks
Please note that this should be done before closing chromium more than twice. Otherwise the bookmarks will be gone forever. Also, in my experience, Chromium should be restarted after running the command for the bookmarks reappear.