diff --git a/core/modules/system/lib/Drupal/system/Tests/Theme/HtmlTagUnitTest.php b/core/modules/system/lib/Drupal/system/Tests/Theme/HtmlTagUnitTest.php
deleted file mode 100644
index b8c6ffb..0000000
--- a/core/modules/system/lib/Drupal/system/Tests/Theme/HtmlTagUnitTest.php
+++ /dev/null
@@ -1,36 +0,0 @@
-<?php
-
-/**
- * @file
- * Definition of Drupal\system\Tests\Theme\HtmlTagUnitTest.
- */
-
-namespace Drupal\system\Tests\Theme;
-
-use Drupal\simpletest\UnitTestBase;
-
-/**
- * Unit tests for theme_html_tag().
- */
-class HtmlTagUnitTest extends UnitTestBase {
-  public static function getInfo() {
-    return array(
-      'name' => 'Theme HTML Tag',
-      'description' => 'Tests theme_html_tag() built-in theme functions.',
-      'group' => 'Theme',
-    );
-  }
-
-  /**
-   * Test function theme_html_tag()
-   */
-  function testThemeHtmlTag() {
-    // Test auto-closure meta tag generation
-    $tag['element'] = array('#tag' => 'meta', '#attributes' => array('name' => 'description', 'content' => 'Drupal test'));
-    $this->assertEqual('<meta name="description" content="Drupal test" />'."\n", theme_html_tag($tag), 'Test auto-closure meta tag generation.');
-
-    // Test title tag generation
-    $tag['element'] = array('#tag' => 'title', '#value' => 'title test');
-    $this->assertEqual('<title>title test</title>'."\n", theme_html_tag($tag), 'Test title tag generation.');
-  }
-}
diff --git a/core/modules/system/lib/Drupal/system/Tests/Theme/PreprocessHtmlTagUnitTest.php b/core/modules/system/lib/Drupal/system/Tests/Theme/PreprocessHtmlTagUnitTest.php
new file mode 100644
index 0000000..e5c18cb
--- /dev/null
+++ b/core/modules/system/lib/Drupal/system/Tests/Theme/PreprocessHtmlTagUnitTest.php
@@ -0,0 +1,41 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\system\Tests\Theme\PreprocessHtmlTagUnitTest.
+ */
+
+namespace Drupal\system\Tests\Theme;
+
+use Drupal\simpletest\UnitTestBase;
+
+/**
+ * Unit tests for template_preprocess_html_tag().
+ */
+class PreprocessHtmlTagUnitTest extends UnitTestBase {
+  public static function getInfo() {
+    return array(
+      'name' => 'Preprocess HTML Tag',
+      'description' => 'Tests template_preprocess_html_tag() function.',
+      'group' => 'Theme',
+    );
+  }
+
+  /**
+   * Tests template_preprocess_html_tag().
+   */
+  function testPreprocessHtmlTag() {
+    // Test running sample meta tag through the preprocess function.
+    $variables['element'] = array('#tag' => 'meta', '#attributes' => array('name' => 'description', 'content' => 'Drupal test'));
+    template_preprocess_html_tag($variables);
+    $this->assertEqual($variables['tag'], 'meta', "'tag' variable is set to 'meta'.");
+    $this->assertTrue(!isset($variables['value']), "'value' variable is not set when no value is passed in.");
+
+    // Test running sample title tag through the preprocess function.
+    $variables = array();
+    $variables['element'] = array('#tag' => 'title', '#value' => 'title test');
+    template_preprocess_html_tag($variables);
+    $this->assertEqual($variables['tag'], 'title', "'tag' variable is set to 'title'.");
+    $this->assertEqual($variables['value'], 'title test', "'value' variable is equal to the value of '#value' in the element array.");
+  }
+}
diff --git a/core/modules/system/templates/html-tag.html.twig b/core/modules/system/templates/html-tag.html.twig
index 74921e4..4118f3b 100644
--- a/core/modules/system/templates/html-tag.html.twig
+++ b/core/modules/system/templates/html-tag.html.twig
@@ -19,7 +19,7 @@
  *
  * @ingroup themeable
  */
- @todo: delete this file once http://drupal.org/node/1825090 is resolved.
+ @todo Delete this file once http://drupal.org/node/1825090 is resolved.
 #}
 {% if value is defined -%}
   <{{ tag }}{{ attributes }}>