OK. That’s frustrating. Chome updated itself to version 12 and apparently cleared all app data storage to implement some new features. New features = great. Wiping out our data without warning/prompting us? Not cool Google. Not cool.
The upshot? It means I’m accelerating the prioritization of online backup and syncing of tag/bookmark data. The other benefit will be access to your data from other machines and (hopefully) shortly thereafter on your mobile phone!