UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.117 Safari/537.36

Steps to reproduce the problem:
The problem is especially pronounced if one has multiple tabs open. To replicate, try force-closing Chrome with at least 20-40 tabs open.

What is the expected behavior?
Recovery should *not block or freeze* the UI thread, or alternatively is not initiated until the user initiates it by clicking on the popup. The default behavior should be to assume the user does NOT want to restore the old session, while still presenting that option to the user. (This may be relevant if for example the browser is actually crashing, or  repeatedly crashes, and the user doesn't want to lose their data.)

If the above is wontfix, then Chrome at least needs a way to disable the functionality, because waiting 4 minutes every time one starts up the computer for Chrome to load is intolerable from a performance (and sanity) perspective. The 'pro'/'for' cases for such an option would be to reduce unnecessary work or (in extreme cases) CPU/disk/memory thrashing. The 'con'/'against' cases for such an option would be option bloat and "why are we not just fixing this?".

Workaround:

On every invocation of any "launch browser" shortcuts or any scripts or programs which launch Chrome or use Chrome as a component, use sed or some other tool (or parse the JSON) of the Preferences file to trick Chrome into believing it exited cleanly. Furthermore a check must be done before invoking such a workaround script to ensure that an instance of Chrome using the same Preference file is not already running (in which case you would be overwriting a Preferences to which Chrome might already have a file handle to, possibly causing issues if Chrome wanted to write to its own Preference file!).

Such a workaround is inelegant because it is feasible it will cause an ever-increasing unbounded amount of corrupt garbage to accumulate on disk slowly over time (e.g. if Chrome happens to have a logging structure it assumes it clears on every "do you want to recover...?" cleanup, which would never occur).

What went wrong?
Chrome will take between almost 1 to 4 minutes to boot up whenever it closes abruptly, such as when the user shuts down. This started happening circa 2010 on both Windows and Linux (and presumably Mac).

relevant stackexchange:
https://superuser.com/questions/461035/disable-google-chrome-session-restore-functionality

Did this work before? Yes circa 2010? maybe it never worked

Chrome version: 66.0.3359.117  Channel: n/a
OS Version: 
Flash Version: