Less general native AveragePool helper
Less general native AveragePool helper

okuta/chainer,hvy/chainer,hvy/chainer,ktnyt/chainer,ktnyt/chainer,keisuke-umezawa/chainer,hvy/chainer,wkentaro/chainer,jnishi/chainer,wkentaro/chainer,jnishi/chainer,jnishi/chainer,pfnet/chainer,ktnyt/chainer,tkerola/chainer,hvy/chainer,jnishi/chainer,ktnyt/chainer,wkentaro/chainer,okuta/chainer,keisuke-umezawa/chainer,niboshi/chainer,keisuke-umezawa/chainer,chainer/chainer,okuta/chainer,chainer/chainer,chainer/chainer,niboshi/chainer,niboshi/chainer,niboshi/chainer,chainer/chainer,wkentaro/chainer,okuta/chainer,keisuke-umezawa/chainer