Remove both through your OS control panel or using Revo uninstaller if they are persistent. You can reinstall Chrome if you really like it. Any free AV program will work fine or you can keep your Avast. Run Malawarebites to get rid of unwanted adware or malware. After that all should be fine.
Anytime you install new programs use custom install, especially if you DL the prog from CNET. A lot of progs come bundled with toolbars and other adware that will be installed if you use the express/easy install. CNET bundles every free prog with things you may not want. You can uncheck the bundled crap when you do a custom install and the custom install is not difficult at all. It frequently just entails unchecking toolbars and adware installation that is bundled with the prog.