Enter the Settings menu, choose 'Personalization' click 'Colors' and scroll down to the switch marked 'Choose your default app mode'.
Change this to 'Dark' and all apps with a native dark mode, including Chrome, will change color. There's no need to restart your browser.
Open 'System Preferences', click 'General', select 'Appearance'.
Select the 'Dark' option. As with Windows, all apps with a native dark mode will change automatically with no further input from you.
Chrome supports dark mode. Learn more about Chrome on the website.