If you have come to Google Chrome from say Firefox you will find the difference in the user interface irritating to say the least particularly when it comes to restoring your last session after an unexpected or accidental shut down.
This worked for me: Open Chrome and Right click on a New Tab, the first option should be a clickable option to Restore, Click and your last session should be restored. I have had the Restore option appear greyed out. If this happens go to Settings> History and click the most recent activity, when this opens repeat previous advice. Hopefully your last session should open.
This was a bit of a suck and see effort on my part as the advice in the various forums I checked were very confusing. If you know a better way post a comment.