Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/modules/views/src/Ajax/ReplaceTitleCommand.php

@@ -0,0 +1,46 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\views\Ajax\ReplaceTitleCommand.
+ */
+
+namespace Drupal\views\Ajax;
+
+use Drupal\Core\Ajax\CommandInterface;
+
+/**
+ * Provides an AJAX command for replacing the page title.
+ *
+ * This command is implemented in Drupal.AjaxCommands.prototype.viewsReplaceTitle.
+ */
+class ReplaceTitleCommand implements CommandInterface {
+
+  /**
+   * The page title to replace.
+   *
+   * @var string
+   */
+  protected $title;
+
+  /**
+   * Constructs a \Drupal\views\Ajax\ReplaceTitleCommand object.
+   *
+   * @param string $title
+   *   The title of the page.
+   */
+  public function __construct($title) {
+    $this->title = $title;
+  }
+
+  /**
+   * Implements \Drupal\Core\Ajax\CommandInterface::render().
+   */
+  public function render() {
+    return array(
+      'command' => 'viewsReplaceTitle',
+      'selector' => $this->title,
+    );
+  }
+
+}