This theme is based on a mockup done by lordalpha1 (http://lordalpha1.deviantart.com/journal/Chronos-Mockup-283071705)
The theme works for both Metacity and Mutter.
First, extract the zip, then copy the theme you want, or both to ~/.themes
Chronos has an x in the corner; Chronos-nx has no x in the corner, just a red button.
Then in GNOME-Tweak-Tool or a similar utility, change the window border theme to your selected variation of Chronos.