The option was removed in latest developer 46 build.

Wow, that is an extremely unfortunate decision. It would be like if Amazon chose to ax their two day shipping option to make room for a 'new and improved' two MONTH delivery service. Giant step in the WRONG direction!
I guess I'm switching back to Firefox for now (albeit begrudgingly).
On the plus side, at least I discovered today that there actually is a way use system colors on the top bar in Firefox: http://www.askvg.com/tip-get-colored-titlebar-back-in-mozilla-firefox-in-windows-10/
^ tip: add the "tab mix plus" add-on and you can change the color of the tab text too

Thanks for Firefox

That option was removed in latest developer build.

Why ?

The option was removed in latest developer 46 build.

Wow, that is an extremely unfortunate decision. It would be like if Amazon chose to ax their two day shipping option to make room for a 'new and improved' two MONTH delivery service. Giant step in the WRONG direction!
I guess I'm switching back to Firefox for now (albeit begrudgingly).
On the plus side, at least I discovered today that there actually is a way use system colors on the top bar in Firefox: http://www.askvg.com/tip-get-colored-titlebar-back-in-mozilla-firefox-in-windows-10/
^ tip: add the "tab mix plus" add-on and you can change the color of the tab text too

Thanks for Firefox

This function(use system color on top bar) does not work in v45.0.2552.812 either.

The option with system colour was perfect for me too. But this function (use system color on top bar) isn't running at v45.

So I returned to Opera 44.0.2510.1457.

Please add option for delete data on exit.

Please add option for delete data on exit.

An option for it may be more useful than one to delete navigation data on exit.

Please add option for delete data on exit.