pinned columns don't have horizontal scrolling

[Gennady77]

Propblem appeareds when we have several pinned colums which are over a width of grid.
Code here:
http://plnkr.co/edit/G8fPEciy06Ou2LOxPkKu?p=preview

Pinned columns go over the age of table without scrolling area of pinned columns. And hide not pinned column

[mportuga]

Adding overflow: hidden to the grid works as a workaround. But we need a more permanent solution.