01_PolyfillSurfaceController.cs

public class UmbracoSurfaceControllerDependencies
{
#if NET
    public IUmbracoContextAccessor UmbracoContextAccessor { get; set; }
    public IUmbracoDatabaseFactory DatabaseFactory { get; set; }
    public ServiceContext Services { get; set; }
    public AppCaches AppCaches { get; set; }
    public IProfilingLogger ProfilingLogger { get; set; }
    public IPublishedUrlProvider PublishedUrlProvider { get; set; }

    public UmbracoSurfaceControllerDependencies(IUmbracoContextAccessor umbracoContextAccessor,
            IUmbracoDatabaseFactory databaseFactory,
            ServiceContext services,
            AppCaches appCaches,
            IProfilingLogger profilingLogger,
            IPublishedUrlProvider publishedUrlProvider)
    {
        UmbracoContextAccessor = umbracoContextAccessor;
        DatabaseFactory = databaseFactory;
        Services = services;
        AppCaches = appCaches;
        ProfilingLogger = profilingLogger;
        PublishedUrlProvider = publishedUrlProvider;
    }
#else 
    // v8 Doesn't actually need deps so it can just be blank
    // but if it did, you'd define the props + constructor for those
    // dependencies in the same way as above
    //
    // public SomeType1 Dependency1 { get; set; }
    // public SomeType2 Dependency2 { get; set; }
    //
    // public UmbracoSurfaceControllerDependencies(SomeType1 dep1, SomeType2 dep2)
    // {
    //      Dependency1 = dep2;
    //      Dependency2 = dep2;
    // }
#endif
}

public abstract class PolyfillSurfaceController : SurfaceController
{
    public AltSurfaceController(UmbracoSurfaceControllerDependencies deps)
#if NET
        : base(deps.UmbracoContextAccessor, deps.DatabaseFactory, deps.Services, deps.AppCaches, deps.PprofilingLogger, deps.PublishedUrlProvider)
#else
        // v8 doesnt have deps, but if it did, you call the base constructore passing the v8 deps from
        // the deps object in the same was as the .NET Core base constructor
        // : base(deps.Dependency1, deps.Dependency2)
#endif
    {

    }
}

02_MySurfaceController.cs

// Surface controllers in v8 and v9 would then become just as follows

public class MySurfaceController : PolyfillSurfaceController
{
    public MySurfaceController(UmbracoSurfaceControllerDependencies deps)
      : base(deps)
    { }
}