core/lib/Drupal/Core/Render/Element/PageTitle.php | 56 +++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/core/lib/Drupal/Core/Render/Element/PageTitle.php b/core/lib/Drupal/Core/Render/Element/PageTitle.php
new file mode 100644
index 0000000..30746e7
--- /dev/null
+++ b/core/lib/Drupal/Core/Render/Element/PageTitle.php
@@ -0,0 +1,56 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Render\Element\PageTitle.
+ */
+
+namespace Drupal\Core\Render\Element;
+
+/**
+ * Provides a render element for the title of an HTML page.
+ *
+ * This represents the title of the HTML page's body.
+ *
+ * @RenderElement("page_title")
+ */
+class PageTitle extends RenderElement {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getInfo() {
+    return [
+      '#title' => NULL,
+      '#pre_render' => [
+        [static::class, 'preRenderPageTitle'],
+      ],
+      '#cache' => [
+        'contexts' => [
+          'route',
+        ],
+      ],
+    ];
+  }
+
+  /**
+   * Renders a page title.
+   *
+   * @param array $element
+   *   A page title render array, with #title either a string or a #markup
+   *   render array.
+   *
+   * @return array
+   *   The updated page title render array, with the title in #markup.
+   */
+  public static function preRenderPageTitle($element) {
+    if (is_array($element['#title'])) {
+      $element += $element['#title'];
+    }
+    else {
+      $element['#markup'] = $element['#title'];
+    }
+    return $element;
+  }
+
+}