The Xamarin.Forms includes DependencyService to help shared code to resolve platform specific implementation. The important thing here is that DependencyService isn’t replace for Dependency Injection container. DependencyService is rather service locator than IoC container. I will show you how they can work together. Although I’m using Autofac as IoC, the proposed design and architecture should be applicable to any IoC Container.
Normally when you create AutoMapper profile, it is you responsibility to register them. However with the dependency injection container (DI) you have great possibility to automate this.