Default browser is Google Hangouts
Solution 1:
As @Kulfy mostly correctly pointed out, there's no NATIVE (but it can be installed) Google Hangouts client. From your screenshot, it lists Firefox very clearly as the default web browser. I suspect there was an issue with the version of Chrome you installed, although I don't see how that would happen. Try reinstalling chrome, making sure to use the latest STABLE release. If that doesn't fix it, try rebooting and see what happens.