Windows 8 comes with two type of applications, Metro Apps & Classic Desktop Apps. The Metro applications are specially designed for touch user interface while desktop applications are classic windows apps that we run on our PC’s all the time. Microsoft currently doesn’t allow Google Chrome or Mozilla Firefox to be installed as Metro App. It is clumsy of Microsoft to not allow other web browsers as Metro applications. Microsoft is taking Apple like approach, Apple currently only allow Safari webkit to be used by browsers. You can not use Chrome on ARM machines but it can be installed on regular PC’s and Chromium Dev built can be installed as Metro App in Windows 8.
There is an experimental Metro App by Chromium team which can run desktop like chrome browser as an Metro App. You can download this application from “Dev channel for Windows” in Chromium Windows section. After the installation just make Google Chrome default web browser and it will become Metro App.
Please note that after making Google Chrome your default web browser you will not be able to use Internet Explorer in Metro mode.
Don’t use Google Chrome as your primary browser because currently it is in Dev state and not suitable for general usage, this Google Chrome version is expected to have crashes and bugs so use it at your own risk.