Source

File: wp-admin/includes/media.php

function media_upload_header() {
	$post_id = isset( $_REQUEST['post_id'] ) ? intval( $_REQUEST['post_id'] ) : 0;

	echo '<script type="text/javascript">post_id = ' . $post_id . ';</script>';

	if ( empty( $_GET['chromeless'] ) ) {
		echo '<div id="media-upload-header">';
		the_media_upload_tabs();
		echo '</div>';
	}
}