Performance/Snappy/Shutdown

I would like to gather a list of things we must persist during shutdown. On shutdown we:

• Do some cache finalization
• persist cookies
• flush places:
  • Clear history on shutdown
  • apply pending page removals (forget about this page) (ideally none)
  • Session annotations - this could be moved to a hash so we don't care
  • apply pending bookmarks changes (ideally none)
• save window geometry in rdf files
• mark session-restore as non-crash
• Module owners <-- please add your feedback