Index: wp-includes/media-template.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- wp-includes/media-template.php	(revision c7058c739d2e19662cf1001b0f3cb6becae27932)
+++ wp-includes/media-template.php	(revision )
@@ -737,13 +737,18 @@
 			<span><?php _e('Columns'); ?></span>
 			<select class="columns" name="columns"
 				data-setting="columns">
-				<?php for ( $i = 1; $i <= 9; $i++ ) : ?>
-					<option value="<?php echo esc_attr( $i ); ?>" <#
-						if ( <?php echo $i ?> == wp.media.galleryDefaults.columns ) { #>selected="selected"<# }
+				<?php
+				    $columns = array( 1, 2, 3, 4, 5, 6, 7, 8, 9 );
+
+				    $columns = apply_filters('gallery_settings_columns', $columns);
+                ?>
+				<?php foreach ( $columns AS $column ) : ?>
+					<option value="<?php echo esc_attr( $column ); ?>" <#
+						if ( <?php echo $column ?> == wp.media.galleryDefaults.columns ) { #>selected="selected"<# }
 					#>>
-						<?php echo esc_html( $i ); ?>
+						<?php echo esc_html( $column ); ?>
 					</option>
-				<?php endfor; ?>
+				<?php endforeach; ?>
 			</select>
 		</label>