message: Avoid unnecessary creation of RuntimeShape
diff: @@ -42,9 +42,13 @@ inline void SpaceToBatchND(const SpaceToBatchParams& params,
  // Extends the input/output shape from 3D to 4D if needed, NHC -> NH1C.
  const RuntimeShape input1_shape =
  - RuntimeShape::ExtendedShape(4, unextended_input1_shape);
  + (unextended_input1_shape.DimensionsCount() == 4)
  + ? unextended_input1_shape
  + : RuntimeShape::ExtendedShape(4, unextended_input1_shape);
  const RuntimeShape output_shape =
  - RuntimeShape::ExtendedShape(4, unextended_output_shape);
  + (unextended_output_shape.DimensionsCount() == 4)
  + ? unextended_output_shape
  + : RuntimeShape::ExtendedShape(4, unextended_output_shape);
  const int depth = input1_shape.Dims(3);
  const int input_width = input1_shape.Dims(2);
  