diff --git a/core/modules/toolbar/toolbar.module b/core/modules/toolbar/toolbar.module
index 4b4e0d8..379b80a 100644
--- a/core/modules/toolbar/toolbar.module
+++ b/core/modules/toolbar/toolbar.module
@@ -197,6 +197,16 @@ function template_preprocess_toolbar(&$variables) {
 }
 
 /**
+ * Implements template_preprocess_HOOK().
+ */
+function template_preprocess_toolbar_tab_wrapper(&$variables) {
+  if (!isset($variables['element']['#attributes'])) {
+    $variables['element']['#attributes'] = array();
+  }
+  $variables['element']['#attributes']['class'][] = 'tab';
+}
+
+/**
  * Returns HTML for wrapping a toolbar tab.
  *
  * Toolbar tabs have a common styling and placement with the toolbar's bar area.
@@ -207,9 +217,8 @@ function template_preprocess_toolbar(&$variables) {
  *     the tray. Properties used: #children and #attributes.
  */
 function theme_toolbar_tab_wrapper(&$variables) {
-  $element = $variables['element'];
-  if (!empty($element['#children'])) {
-    $element['#attributes']['class'][] = 'tab';
+  if (!empty($variables['element']['#children'])) {
+    $element = $variables['element'];
     return '<div' . new Attribute($element['#attributes']) . '>' . $element['#children'] . '</div>';
   }
 }
@@ -248,6 +257,26 @@ function theme_toolbar_tray_toggle(&$variables) {
 }
 
 /**
+ * Implements template_preprocess_HOOK().
+ */
+function template_preprocess_toolbar_tray_wrapper(&$variables) {
+  if (!isset($variables['element']['#attributes'])) {
+    $variables['element']['#attributes'] = array();
+  }
+  if (!empty($variables['element']['#toolbar_identifier'])) {
+    $group = $variables['element']['#toolbar_identifier'];
+    $variables['element']['#attributes'] += array(
+      'id' => 'toolbar-tray-' . $group,
+      'data-toolbar-tray' => $group,
+      'aria-owned-by' => 'toolbar-tab-' . $group,
+    );
+    $variables['element']['#attributes']['class'][] = 'tray';
+    $variables['element']['#attributes']['class'][] = 'tray-' . $group;
+    $variables['element']['#attributes']['class'][] = 'overlay-displace-top';
+  }
+}
+
+/**
  * Returns HTML for wrapping a toolbar tray.
  *
  * Used in combination with theme_toolbar_tray_toggle() to create an
@@ -260,25 +289,11 @@ function theme_toolbar_tray_toggle(&$variables) {
  *     and #heading.
  */
 function theme_toolbar_tray_wrapper(&$variables) {
-  $element = $variables['element'];
-  if (!empty($element['#children'])) {
-    if (!empty($element['#toolbar_identifier'])) {
-      $group = $element['#toolbar_identifier'];
-      if (!isset($element['#attributes'])) {
-        $element['#attributes'] = array();
-      }
-      $element['#attributes'] += array(
-        'id' => 'toolbar-tray-' . $group,
-        'data-toolbar-tray' => $group,
-        'aria-owned-by' => 'toolbar-tab-' . $group,
-      );
-      $element['#attributes']['class'][] = 'tray';
-      $element['#attributes']['class'][] = 'tray-' . $group;
-      $element['#attributes']['class'][] = 'overlay-displace-top';
-    }
+  if (!empty($variables['element']['#children'])) {
+    $element = $variables['element'];
     // Print a heading in the tray if one exists.
     $heading = (isset($element['#heading'])) ? '<h2 class="element-invisible">' . $element['#heading'] . '</h2>' : '';
-    return '<div' . new Attribute($element['#attributes']) . '><div class="lining clearfix">' . $heading . $variables['element']['#children'] . '</div></div>';
+    return '<div' . new Attribute($element['#attributes']) . '><div class="lining clearfix">' . $heading . $element['#children'] . '</div></div>';
   }
 }