Bug 892875 - Put background thumbnails behind a preference, and disable that preference during tests.  r=adw
Bug 870100 (part 1) - regenerate stale page thumbnails on demand, and send notification when done.  r=adw
Bug 870100 (part 2) - about:newtab observes notifications for new page thumbnails.  r=ttaubert
Bug 896312 - social.cookies-get message returns an empty cookie instead of an empty array when no cookies.  r=mixedpuppy