I tried this and works good :
At My hosting WHM (create new account)
1- Use the nameservers specified at the Domain's Registrar (my own DNS)
2- selected the option Remote Mail Exchanger .
PS: No need to add anything in hosting MX records.
At My domain Manger which is on name.com
1- enable Google Apps (when you agree the DNS will changed to name.com DNS default)
Note that later on you have to change the default name.com DNS to your own DNS>
2- Google Apps Automatically created new records in Domain MX records Management:
3- go to Edit DNS name server, and deleted the default name.com DNS and added my (my own DNS)
PS:No need to add anything in Domain MX records.