Returns HTML for a progress bar.
Note that the core Batch API uses this only for non-JavaScript batch jobs.
$variables: An associative array containing:
function theme_progress_bar($variables) {
$output = '<div id="progress" class="progress">';
$output .= '<div class="bar"><div class="filled" style="width: ' . $variables['percent'] . '%"></div></div>';
$output .= '<div class="percentage">' . $variables['percent'] . '%</div>';
$output .= '<div class="message">' . $variables['message'] . '</div>';
$output .= '</div>';
return $output;
}