UserAgent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:56.0) Gecko/20100101 Firefox/56.0

Steps to reproduce the problem:
1- Put a listener with onRemoved event 
2- Discard a tab
3- onRemoved is fired even if the tab was not closed but only discarded to save memory.

See the included video to have a better understanding of the issue it cause. 

What is the expected behavior?

What went wrong?
I'm using an extension (Tabulator https://github.com/akhaku/tabulator ) that use the onRemoved event to delete the screenshot of the tabs when they are closed but the problem is  that the event is also fired when the tabs goes in discarded state too.

When the tabs are discarded via "chrome.tabs.discard" by an extension or chrome itself it should not fire a, "onRemoved" event since the tab is nor closed.

IMO one good solution would be to have an event to detect if tab is discarded. 

Here's a video to demonstrate the problem that this false message cause with this extension and many other that expect to receive the onRemoved event only when a tab is closed and not when a tabs enter in a discarded state: http://screencast-o-matic.com/watch/cF1IfxFhMj

If it is not enough clear let me know and I will to make my best to answer you questions. 

Regards !

Did this work before? No 

Does this work in other browsers? No

Chrome version: 66.0.3359.117 (Build officiel) (32 bits)  Channel: stable
OS Version: 6.1 (Windows 7, Windows Server 2008 R2)
Flash Version: Shockwave Flash 28.0 r0