public GenericDraweeHierarchyBuilder setProgressBarImage(
      Drawable progressBarDrawable, @Nullable ScalingUtils.ScaleType progressBarImageScaleType) {
    mProgressBarImage = progressBarDrawable;
    mProgressBarImageScaleType = progressBarImageScaleType;
    return this;
  }
Sets the progress bar image and its scale type.

@param progressBarDrawable drawable to be used as progress bar image
@param progressBarImageScaleType scale type for the progress bar image
@return modified instance of this builder
drawee/src/main/java/com/facebook/drawee/generic/GenericDraweeHierarchyBuilder.java