Re-remove deprecated API.

The original of this PR was f53c247d10acbaacb0d61824cfce888c4b0520d2 by @tenderlove.
But f53c247d10acbaacb0d61824cfce888c4b0520d2  was reverted  by 4d073df43d6ecd99ab04dbd0773a61559325efb8 , because we should remove this old api in Rails 4.1.

BTW: I couldn't merge f53c247d10acbaacb0d61824cfce888c4b0520d2 because of  complicated conflict ;)