Give a little bit of RP to a friend?

I know you can buy someone RP but what if they need 5 RP to buy a skin. My friend had 515 and he wanted Chosen Master Yi but he didn't have enough so he just bought Assassin Master Y. One time I had 478 but needed a few more to get a Kennen skin when it was on sale. What if you could donate some RP (100 max) to a friend in need. It would be really helpful to a lot of people.