Just noticed recently that Yi have done the necessary and have made their Yi Home cameras viewable using Google Home and Chromecast. As the Yi cameras have been popular on HUKD I thought it would be useful to highlight this new functionality.
The process is described discussed in this thread on the Yi Forums.
The thread is a bit rambling as the link between Google Home and Yi was not initially stable but it's working for me at the moment. Although I do not have any, apparently the Yi IOT devices are now also supported. Note that some of the oldest Yi home camera devices do not work, I have an indoor 720p camera that doesn't work with Google Home.
Hope this is useful.