Image dimensions callback; Scale.
array $dimensions: Dimensions to be modified - an array with components width and height, in pixels.
array $data: An array of attributes to use when performing the scale effect with the following items:
function image_scale_dimensions(array &$dimensions, array $data) {
if ($dimensions['width'] && $dimensions['height']) {
image_dimensions_scale($dimensions, $data['width'], $data['height'], $data['upscale']);
}
}