Yeah, that "wallpaper" you installed probably was an app ("live wallpapers" are apps themselves, and there are many apps whose purpose is to provide a selection of wallpapers).
There is no distinction between a "virus" and an app. Android malware takes the form of "trojans", i.e. malware hidden inside an app that the user installs. So I'm 100% certain that is what happened here: you installed adware when you downloaded that wallpaper. Whether the adware is the wallpaper itself (if it's a live wallpaper), a "wallpaper app" or another app that was downloaded and which you installed (allowed Chrome to install) at the same time, the adware is an app and if you find and delete it the ads will stop.