Manifest flag enable_top_isolation has been "moved up" in the hirarchy: Now it's per app and not per windows - means, it's under the "data" node and not the "window" node. Note that it's backward compatible (means that if one of the app windows set this flag in the manifest - it will auto-merge to the entire app).
Logs: now end with the extension "log" (instead of numbers). In addition, logs file names are now counted where the last number one is the newest file.