https://www.theverge.com/2019/2/7/18215473/google-chrome-dark-mode-windows-macos-support

Google is testing out a new dark mode for its Chrome browser. 9to5Google reports that both macOS and Windows 10 will get dark mode support, and it’s currently in testing in the latest Canary development builds of Chrome. Google’s browser appears to enable dark mode by default, picking up your system settings on macOS and Windows.

It’s not entirely clear how Google plans to introduce its dark mode for Chrome. We’ve tested it in the latest Chrome Canary release. On some systems, it respects the system-wide dark mode, and on others, it does not. Google must still be experimenting with the best way to roll this out on both macOS and Windows 10.