As of 27 Feb 2016 project was moved to GNOME infrastructure.
Wiki: https://wiki.gnome.org/Projects/GnomeShellIntegrationForChrome
Installation instructions: https://wiki.gnome.org/Projects/GnomeShellIntegrationForChrome/Installation
Source code: https://git.gnome.org/browse/chrome-gnome-shell
Github mirrors:
Issues: https://github.com/nE0sIghT/chrome-gnome-shell-mirror/issues
Pull requests: https://github.com/nE0sIghT/chrome-gnome-shell-mirror/pulls