U4-10385 Examine indexing performance bottleneck: IUserService.GetProfileById which is not cached

src/Umbraco.Core/Models/Membership/User.cs

@@ -17,7 +17,7 @@ namespace Umbraco.Core.Models.Membership
     /// </summary>    
     [Serializable]
     [DataContract(IsReference = true)]
-    public class User : Entity, IUser
+    public class User : Entity, IUser, IProfile
     {
         /// <summary>
         /// Constructor for creating a new/empty user

src/Umbraco.Core/Services/UserService.cs

@@ -701,12 +701,11 @@ namespace Umbraco.Core.Services
         /// <param name="id">Id of the User to retrieve</param>
         /// <returns><see cref="IProfile"/></returns>
         public IProfile GetProfileById(int id)
-        {
-            using (var uow = UowProvider.GetUnitOfWork(readOnly: true))
-            {
-                var repository = RepositoryFactory.CreateUserRepository(uow);
-                return repository.GetProfile(id);
-            }
+        {
+            //This is called a TON. Go get the full user from cache which should already be IProfile
+            var fullUser = GetUserById(id);
+            var asProfile = fullUser as IProfile;
+            return asProfile ?? new UserProfile(fullUser.Id, fullUser.Name);
         }
 
         /// <summary>