Mozilla wants Firefox users to discover the most useful session restore feature, that’s why they want to add button for it in the tab bar. The button labelled ‘Restore Tabs From Last Time’ will only appear to the user when Firefox browser has one tab or two tabs with first run page, otherwise it won’t be visible, clicking on it restores the tabs from previous session.
The company is currently doing tests and if all goes well, we may see the session restore button in the near future on the Firefox tab bar. FYI, Firefox already offers’ Restore previous session’ button on its home page (you can reach by visiting about:home in address bar). With this change, the session restore feature will be used by more users.
Firefox Session Restore button
Mozilla also wants to show a notification to user who uses the button more often to change the startup preference to always restore session, doing so doesn’t affect Firefox startup performance as tabs on demand feature enabled by default in Firefox browser.