check for valid data before upgrading and assign defaults after cleaning

[bridiver]

Fixes #3550

Auditors: @bbondy @bsclifton

[bbondy]

Is there an issue for this? If not please post and update PR. Also to ensure it is tested the issue should be marked in the 0.11.6 milestone.

[bridiver]

@bsclifton can you create an issue for the original problem you had?

[bsclifton]

@bridiver beat me to creating an issue, but I captured some good steps 😄

Check out the issue and STR here

[bsclifton]

To verify the fix

• Ensure all Brave instances are closed
• Download session-store-1_bsc0.11.1.zip
• Unzip / move this session file to the appropriate location (Mac is ~/Libraries/Application\ Support/brave/), making sure to rename it as session-store-1
• Install a version of Brave which has the fix
• Launch into Brave and inspect the browser developer tools (Shift + F8)

[bbondy]

++