Add gpu markers.
Add gpu markers.

jnishi/chainer,hvy/chainer,ktnyt/chainer,aonotas/chainer,chainer/chainer,hvy/chainer,jnishi/chainer,niboshi/chainer,wkentaro/chainer,hvy/chainer,ktnyt/chainer,okuta/chainer,chainer/chainer,okuta/chainer,ktnyt/chainer,okuta/chainer,chainer/chainer,keisuke-umezawa/chainer,niboshi/chainer,hvy/chainer,keisuke-umezawa/chainer,anaruse/chainer,jnishi/chainer,niboshi/chainer,chainer/chainer,tkerola/chainer,pfnet/chainer,rezoo/chainer,niboshi/chainer,okuta/chainer,keisuke-umezawa/chainer,wkentaro/chainer,wkentaro/chainer,wkentaro/chainer,ktnyt/chainer,ronekko/chainer,jnishi/chainer,keisuke-umezawa/chainer