style: separate base class members

Author: voltjia

src/base/fractional_max_pool2d_backward_grad_input.h

@@ -34,17 +34,29 @@ class FractionalMaxPool2dBackwardGradInput
 
  protected:
   Tensor::Shape grad_output_shape_;
+
   Tensor::Strides grad_output_strides_;
+
   DataType grad_output_type_;
+
   Tensor::Shape self_shape_;
+
   Tensor::Strides self_strides_;
+
   DataType self_type_;
+
   Tensor::Shape indices_shape_;
+
   Tensor::Strides indices_strides_;
+
   DataType indices_type_;
+
   Tensor::Shape grad_input_shape_;
+
   Tensor::Strides grad_input_strides_;
+
   DataType grad_input_type_;
+
   int device_index_{0};
 };