When you are writing a long blog post, suddenly the browser felt sick and shut down... (;_;) Sorry, but your two-hour effort is gone!
We don't wont any of that, do we?
Here comes an extension that saves you from such pain.
Just install it. No settings what so ever. This extension saves your texts up to 10 minutes after the tab is closed. When you next open the same URL, and if this extension found a saved text, it restores the text automatically.
(It may ask you to restore the text if the page already has some text as well as your text. For example, some page has "Please write comments here" text but of course you overwrites that. When this extension finds "Please write comments here" and your text, it can't tell which one is more important to you. So it asks you "You have some editing text. Restore?")