diff --git a/core/lib/Drupal/Core/Field/WidgetBase.php b/core/lib/Drupal/Core/Field/WidgetBase.php
index 5a4740b..575daf9 100644
--- a/core/lib/Drupal/Core/Field/WidgetBase.php
+++ b/core/lib/Drupal/Core/Field/WidgetBase.php
@@ -85,7 +85,7 @@ public function form(FieldItemListInterface $items, array &$form, FormStateInter
       $delta = isset($get_delta) ? $get_delta : 0;
       $element = array(
         '#title' => $this->fieldDefinition->getLabel(),
-        '#description' => FieldFilteredString::create(\Drupal::token()->replace($this->fieldDefinition->getDescription())->renderToHtml()),
+        '#description' => FieldFilteredString::create(\Drupal::token()->replace($this->fieldDefinition->getDescription())),
       );
       $element = $this->formSingleElement($items, $delta, $element, $form, $form_state);
 
@@ -164,9 +164,7 @@ protected function formMultipleElements(FieldItemListInterface $items, array &$f
     }
 
     $title = $this->fieldDefinition->getLabel();
-    debug($this->fieldDefinition->getDescription());
-    debug(\Drupal::token()->replace($this->fieldDefinition->getDescription()));
-    $description = FieldFilteredString::create(\Drupal::token()->replace($this->fieldDefinition->getDescription())->renderToHtml());
+    $description = FieldFilteredString::create(\Drupal::token()->replace($this->fieldDefinition->getDescription()));
 
     $elements = array();
 
diff --git a/core/lib/Drupal/Core/Render/Renderer.php b/core/lib/Drupal/Core/Render/Renderer.php
index 5b3bbe4..c2e03c9 100644
--- a/core/lib/Drupal/Core/Render/Renderer.php
+++ b/core/lib/Drupal/Core/Render/Renderer.php
@@ -9,7 +9,6 @@
 
 use Drupal\Component\Utility\Html;
 use Drupal\Component\Utility\SafeMarkup;
-use Drupal\Component\Utility\SafeStringInterface;
 use Drupal\Component\Utility\Xss;
 use Drupal\Core\Access\AccessResultInterface;
 use Drupal\Core\Cache\Cache;
@@ -733,11 +732,7 @@ protected function ensureMarkupIsSafe(array $elements) {
     }
 
     if (!empty($elements['#plain_text'])) {
-      $string = $elements['#plain_text'];
-      if (!SafeMarkup::isSafe($string)) {
-        $string = Html::escape($string)
-      }
-      $elements['#markup'] = SafeString::create($string);
+      $elements['#markup'] = SafeString::create(Html::escape($elements['#plain_text']));
     }
     elseif (!SafeMarkup::isSafe($elements['#markup'])) {
       // The default behaviour is to XSS filter using the admin tag list.
diff --git a/core/lib/Drupal/Core/Utility/Token.php b/core/lib/Drupal/Core/Utility/Token.php
index c7a67ca..d41102b 100644
--- a/core/lib/Drupal/Core/Utility/Token.php
+++ b/core/lib/Drupal/Core/Utility/Token.php
@@ -8,8 +8,7 @@
 namespace Drupal\Core\Utility;
 
 use Drupal\Component\Utility\Html;
-use Drupal\Component\Utility\PlainTextOutput;
-use Drupal\Component\Utility\SafeMarkup;
+use Drupal\Component\Utility\SafeStringInterface;
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Cache\CacheableDependencyInterface;
 use Drupal\Core\Cache\CacheBackendInterface;
@@ -144,7 +143,9 @@ public function __construct(ModuleHandlerInterface $module_handler, CacheBackend
    * Replaces all tokens in a given string with appropriate values.
    *
    * @param string $text
-   *   A plain text string potentially containing replaceable tokens.
+   *   A HTML string containing replaceable tokens. The caller is responsible
+   *   for calling \Drupal\Component\Utility\Html::escape() in case the expected
+   *   input was plain text.
    * @param array $data
    *   (optional) An array of keyed objects. For simple replacement scenarios
    *   'node', 'user', and others are common keys, with an accompanying node or
@@ -178,15 +179,19 @@ public function __construct(ModuleHandlerInterface $module_handler, CacheBackend
    *   method creates a local one, and applies the collected metadata to the
    *   Renderer's currently active render context.
    *
-   * @return \Drupal\Core\Utility\TokenString
-   *   The token result string which is an instance of SafeStringInterface, but
-   *   it casts to plain text by default. For usages of this API as HTML, read
-   *   more on \Drupal\Core\Utility\TokenString itself.
+   * @return string
+   *   The token result is the entered HTML text with tokens replaced. The
+   *   caller is responsible for choosing the right escaping / sanitization. If
+   *   its intended to be used as plain text, the usage of
+   *   PlainTextOutput::renderFromHtml() is suggested. If the result is just
+   *   printed as part of a template relying on twig autoescaping is possible,
+   *   otherwise for example the result can be put into #markup, in which case
+   *   it would be xss admin filtered.
    */
   public function replace($text, array $data = array(), array $options = array(), BubbleableMetadata $bubbleable_metadata = NULL) {
     $text_tokens = $this->scan($text);
     if (empty($text_tokens)) {
-      return TokenString::create($text);
+      return $text;
     }
 
     $bubbleable_metadata_is_passed_in = (bool) $bubbleable_metadata;
@@ -211,7 +216,7 @@ public function replace($text, array $data = array(), array $options = array(),
     $values = [];
     foreach ($replacements as $token => $value) {
       $tokens[] = $token;
-      $values[] = SafeMarkup::isSafe($value) ? $value : Html::escape($value);
+      $values[] = $value instanceof SafeStringInterface ? $value : Html::escape($value);
     }
 
     // If a local $bubbleable_metadata object was created, apply the metadata
@@ -222,7 +227,7 @@ public function replace($text, array $data = array(), array $options = array(),
       $this->renderer->render($build);
     }
 
-    return TokenString::create(str_replace($tokens, $values, $text));
+    return str_replace($tokens, $values, $text);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Utility/TokenString.php b/core/lib/Drupal/Core/Utility/TokenString.php
deleted file mode 100644
index bb81867..0000000
--- a/core/lib/Drupal/Core/Utility/TokenString.php
+++ /dev/null
@@ -1,58 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\Core\Utility\TokenString.
- */
-
-namespace Drupal\Core\Utility;
-
-use Drupal\Component\Utility\Html;
-use Drupal\Component\Utility\SafeStringInterface;
-use Drupal\Component\Utility\SafeStringTrait;
-use Drupal\Component\Utility\Xss;
-
-/**
- * Contains the result of a token replacement.
- *
- * The string is casted to a plain string by default, but by calling ::getRaw()
- * the replaced value can be accessed. This value is xss filtered by default.
- *
- * @see \Drupal\Core\Utility\Token::replace()
- */
-class TokenString implements SafeStringInterface {
-
-  use SafeStringTrait;
-
-  /**
-   * {@inheritdoc}
-   */
-  public static function create($string) {
-    $safe_string = new static();
-    $safe_string->string = $string;
-    return $safe_string;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function __toString() {
-    return Html::escape($this->string);
-  }
-
-  /**
-   * Returns the XSS filtered raw string.
-   *
-   * Use this method just in case you output a full HTML fragment. Do not pass
-   * this
-   *
-   * @param array $html_tags
-   *   An array of HTML tags.
-   *
-   * @return string
-   */
-  public function renderToHtml(array $html_tags = NULL) {
-    return Xss::filter($this->string, $html_tags);
-  }
-
-}
diff --git a/core/modules/action/src/Plugin/Action/EmailAction.php b/core/modules/action/src/Plugin/Action/EmailAction.php
index 252428c..4c68e1d 100644
--- a/core/modules/action/src/Plugin/Action/EmailAction.php
+++ b/core/modules/action/src/Plugin/Action/EmailAction.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\action\Plugin\Action;
 
+use Drupal\Component\Utility\PlainTextOutput;
 use Drupal\Core\Access\AccessResult;
 use Drupal\Core\Action\ConfigurableActionBase;
 use Drupal\Core\Entity\EntityManagerInterface;
@@ -127,7 +128,7 @@ public function execute($entity = NULL) {
       $this->configuration['node'] = $entity;
     }
 
-    $recipient = $this->token->replace($this->configuration['recipient'], $this->configuration);
+    $recipient = PlainTextOutput::renderFromHtml($this->token->replace($this->configuration['recipient'], $this->configuration));
 
     // If the recipient is a registered user with a language preference, use
     // the recipient's preferred language. Otherwise, use the system default
diff --git a/core/modules/comment/src/Tests/CommentTokenReplaceTest.php b/core/modules/comment/src/Tests/CommentTokenReplaceTest.php
index 9d530ba..85f09dc 100644
--- a/core/modules/comment/src/Tests/CommentTokenReplaceTest.php
+++ b/core/modules/comment/src/Tests/CommentTokenReplaceTest.php
@@ -117,7 +117,7 @@ function testCommentTokenReplacement() {
     foreach ($tests as $input => $expected) {
       $bubbleable_metadata = new BubbleableMetadata();
       $output = $token_service->replace($input, array('comment' => $comment), array('langcode' => $language_interface->getId()), $bubbleable_metadata);
-      $this->assertEqual($output->renderToHtml(), $expected, format_string('Comment token %token replaced.', array('%token' => $input)));
+      $this->assertEqual($output, $expected, format_string('Comment token %token replaced.', array('%token' => $input)));
       $this->assertEqual($bubbleable_metadata, $metadata_tests[$input]);
     }
 
@@ -126,7 +126,7 @@ function testCommentTokenReplacement() {
     $comment->setOwnerId(0)->setAuthorName($author_name);
     $input = '[comment:author]';
     $output = $token_service->replace($input, array('comment' => $comment), array('langcode' => $language_interface->getId()));
-    $this->assertEqual($output->renderToHtml(), Html::escape($author_name), format_string('Comment author token %token replaced.', array('%token' => $input)));
+    $this->assertEqual($output, Html::escape($author_name), format_string('Comment author token %token replaced.', array('%token' => $input)));
 
     // Load node so comment_count gets computed.
     $node = Node::load($node->id());
@@ -138,7 +138,7 @@ function testCommentTokenReplacement() {
 
     foreach ($tests as $input => $expected) {
       $output = $token_service->replace($input, array('entity' => $node, 'node' => $node), array('langcode' => $language_interface->getId()));
-      $this->assertEqual($output->renderToHtml(), $expected, format_string('Node comment token %token replaced.', array('%token' => $input)));
+      $this->assertEqual($output, $expected, format_string('Node comment token %token replaced.', array('%token' => $input)));
     }
   }
 
diff --git a/core/modules/node/src/Tests/NodeTokenReplaceTest.php b/core/modules/node/src/Tests/NodeTokenReplaceTest.php
index 78d6531..d8c9ddf 100644
--- a/core/modules/node/src/Tests/NodeTokenReplaceTest.php
+++ b/core/modules/node/src/Tests/NodeTokenReplaceTest.php
@@ -105,7 +105,7 @@ function testNodeTokenReplacement() {
     foreach ($tests as $input => $expected) {
       $bubbleable_metadata = new BubbleableMetadata();
       $output = $this->tokenService->replace($input, array('node' => $node), array('langcode' => $this->interfaceLanguage->getId()), $bubbleable_metadata);
-      $this->assertEqual($output->renderToHtml(), $expected, format_string('Node token %token replaced.', array('%token' => $input)));
+      $this->assertEqual($output, $expected, format_string('Node token %token replaced.', array('%token' => $input)));
       $this->assertEqual($bubbleable_metadata, $metadata_tests[$input]);
     }
 
@@ -127,7 +127,7 @@ function testNodeTokenReplacement() {
 
     foreach ($tests as $input => $expected) {
       $output = $this->tokenService->replace($input, array('node' => $node), array('language' => $this->interfaceLanguage));
-      $this->assertEqual($output->renderToHtml(), $expected, format_string('Node token %token replaced for node without a summary.', array('%token' => $input)));
+      $this->assertEqual($output, $expected, format_string('Node token %token replaced for node without a summary.', array('%token' => $input)));
     }
   }
 
diff --git a/core/modules/system/src/Tests/System/TokenReplaceUnitTest.php b/core/modules/system/src/Tests/System/TokenReplaceUnitTest.php
index 0af566a..8330e67 100644
--- a/core/modules/system/src/Tests/System/TokenReplaceUnitTest.php
+++ b/core/modules/system/src/Tests/System/TokenReplaceUnitTest.php
@@ -130,7 +130,7 @@ public function testSystemSiteTokenReplacement() {
     foreach ($tests as $input => $expected) {
       $bubbleable_metadata = new BubbleableMetadata();
       $output = $this->tokenService->replace($input, array(), array('langcode' => $this->interfaceLanguage->getId()), $bubbleable_metadata);
-      $this->assertEqual($output->renderToHtml(), $expected, format_string('System site information token %token replaced.', array('%token' => $input)));
+      $this->assertEqual($output, $expected, format_string('System site information token %token replaced.', array('%token' => $input)));
       $this->assertEqual($bubbleable_metadata, $metadata_tests[$input]);
     }
   }
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index a8477d3..e21c2c8 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -5,6 +5,7 @@
  * Configuration system that lets administrators modify the workings of the site.
  */
 
+use Drupal\Component\Utility\PlainTextOutput;
 use Drupal\Component\Utility\UrlHelper;
 use Drupal\Core\Asset\AttachedAssetsInterface;
 use Drupal\Core\Cache\Cache;
@@ -1290,7 +1291,7 @@ function system_mail($key, &$message, $params) {
 
   $context = $params['context'];
 
-  $subject = $token_service->replace($context['subject'], $context);
+  $subject = PlainTextOutput::renderFromHtml($token_service->replace($context['subject'], $context));
   $body = $token_service->replace($context['message'], $context);
 
   $message['subject'] .= str_replace(array("\r", "\n"), '', $subject);
diff --git a/core/modules/taxonomy/src/Tests/TokenReplaceTest.php b/core/modules/taxonomy/src/Tests/TokenReplaceTest.php
index 709fb43..c1b0795 100644
--- a/core/modules/taxonomy/src/Tests/TokenReplaceTest.php
+++ b/core/modules/taxonomy/src/Tests/TokenReplaceTest.php
@@ -110,7 +110,7 @@ function testTaxonomyTokenReplacement() {
     foreach ($tests as $input => $expected) {
       $bubbleable_metadata = new BubbleableMetadata();
       $output = $token_service->replace($input, array('term' => $term1), array('langcode' => $language_interface->getId()), $bubbleable_metadata);
-      $this->assertEqual($output->renderToHtml(), $expected, format_string('Sanitized taxonomy term token %token replaced.', array('%token' => $input)));
+      $this->assertEqual($output, $expected, format_string('Sanitized taxonomy term token %token replaced.', array('%token' => $input)));
       $this->assertEqual($bubbleable_metadata, $metadata_tests[$input]);
     }
 
@@ -131,7 +131,7 @@ function testTaxonomyTokenReplacement() {
 
     foreach ($tests as $input => $expected) {
       $output = $token_service->replace($input, array('term' => $term2), array('langcode' => $language_interface->getId()));
-      $this->assertEqual($output->renderToHtml(), $expected, format_string('Sanitized taxonomy term token %token replaced.', array('%token' => $input)));
+      $this->assertEqual($output, $expected, format_string('Sanitized taxonomy term token %token replaced.', array('%token' => $input)));
     }
 
     // Generate and test sanitized tokens.
@@ -147,7 +147,7 @@ function testTaxonomyTokenReplacement() {
 
     foreach ($tests as $input => $expected) {
       $output = $token_service->replace($input, array('vocabulary' => $this->vocabulary), array('langcode' => $language_interface->getId()));
-      $this->assertEqual($output->renderToHtml(), $expected, format_string('Sanitized taxonomy vocabulary token %token replaced.', array('%token' => $input)));
+      $this->assertEqual($output, $expected, format_string('Sanitized taxonomy vocabulary token %token replaced.', array('%token' => $input)));
     }
   }
 }
diff --git a/core/modules/tour/src/Plugin/tour/tip/TipPluginText.php b/core/modules/tour/src/Plugin/tour/tip/TipPluginText.php
index d3f8fb6..6bb2338 100644
--- a/core/modules/tour/src/Plugin/tour/tip/TipPluginText.php
+++ b/core/modules/tour/src/Plugin/tour/tip/TipPluginText.php
@@ -122,7 +122,7 @@ public function getAttributes() {
   public function getOutput() {
     $output = '<h2 class="tour-tip-label" id="tour-tip-' . $this->getAriaId() . '-label">' . Html::escape($this->getLabel()) . '</h2>';
     $tags = Xss::getHtmlTagList();
-    $output .= '<p class="tour-tip-body" id="tour-tip-' . $this->getAriaId() . '-contents">' . $this->token->replace($this->getBody())->renderToHtml() . '</p>';
+    $output .= '<p class="tour-tip-body" id="tour-tip-' . $this->getAriaId() . '-contents">' . $this->token->replace($this->getBody()) . '</p>';
     return array('#markup' => $output);
   }
 
diff --git a/core/modules/user/src/Tests/UserTokenReplaceTest.php b/core/modules/user/src/Tests/UserTokenReplaceTest.php
index 1840035..142c6fe 100644
--- a/core/modules/user/src/Tests/UserTokenReplaceTest.php
+++ b/core/modules/user/src/Tests/UserTokenReplaceTest.php
@@ -108,7 +108,7 @@ function testUserTokenReplacement() {
     foreach ($tests as $input => $expected) {
       $bubbleable_metadata = new BubbleableMetadata();
       $output = $token_service->replace($input, array('user' => $account), array('langcode' => $language_interface->getId()), $bubbleable_metadata);
-      $this->assertEqual($output->renderToHtml(), $expected, format_string('User token %token replaced.', array('%token' => $input)));
+      $this->assertEqual($output, $expected, format_string('User token %token replaced.', array('%token' => $input)));
       $this->assertEqual($bubbleable_metadata, $metadata_tests[$input]);
     }
 
@@ -128,7 +128,7 @@ function testUserTokenReplacement() {
     foreach ($tests as $input => $expected) {
       $bubbleable_metadata = new BubbleableMetadata();
       $output = $token_service->replace($input, array('user' => $anonymous_user), array('langcode' => $language_interface->getId()), $bubbleable_metadata);
-      $this->assertEqual($output->renderToHtml(), $expected, format_string('Sanitized user token %token replaced.', array('%token' => $input)));
+      $this->assertEqual($output, $expected, format_string('Sanitized user token %token replaced.', array('%token' => $input)));
       $this->assertEqual($bubbleable_metadata, $metadata_tests[$input]);
     }
 
@@ -141,7 +141,7 @@ function testUserTokenReplacement() {
     $link = \Drupal::url('user.page', [], array('absolute' => TRUE));
     foreach ($tests as $input => $expected) {
       $output = $token_service->replace($input, array('user' => $account), array('langcode' => $language_interface->getId(), 'callback' => 'user_mail_tokens', 'clear' => TRUE));
-      $this->assertTrue(strpos($output->renderToHtml(), $link) === 0, 'Generated URL is in interface language.');
+      $this->assertTrue(strpos($output, $link) === 0, 'Generated URL is in interface language.');
     }
 
     // Generate tokens with the user's preferred language.
@@ -150,7 +150,7 @@ function testUserTokenReplacement() {
     $link = \Drupal::url('user.page', [], array('language' => \Drupal::languageManager()->getLanguage($account->getPreferredLangcode()), 'absolute' => TRUE));
     foreach ($tests as $input => $expected) {
       $output = $token_service->replace($input, array('user' => $account), array('callback' => 'user_mail_tokens', 'clear' => TRUE));
-      $this->assertTrue(strpos($output->renderToHtml(), $link) === 0, "Generated URL is in the user's preferred language.");
+      $this->assertTrue(strpos($output, $link) === 0, "Generated URL is in the user's preferred language.");
     }
 
     // Generate tokens with one specific language.
@@ -158,7 +158,7 @@ function testUserTokenReplacement() {
     foreach ($tests as $input => $expected) {
       foreach (array($user1, $user2) as $account) {
         $output = $token_service->replace($input, array('user' => $account), array('langcode' => 'de', 'callback' => 'user_mail_tokens', 'clear' => TRUE));
-        $this->assertTrue(strpos($output->renderToHtml(), $link) === 0, "Generated URL in in the requested language.");
+        $this->assertTrue(strpos($output, $link) === 0, "Generated URL in in the requested language.");
       }
     }
 
@@ -168,6 +168,6 @@ function testUserTokenReplacement() {
     $input = '[user:display-name] [current-user:display-name]';
     $expected = "<em>{$user1->id()}</em> <em>{$user2->id()}</em>";
     $output = $token_service->replace($input, ['user' => $user1]);
-    $this->assertEqual($output->renderToHtml(), $expected, SafeMarkup::format('User token %token does not escape safe markup.', ['%token' => 'display-name']));
+    $this->assertEqual($output, $expected, SafeMarkup::format('User token %token does not escape safe markup.', ['%token' => 'display-name']));
   }
 }
diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index 0247597..ba4e6bd 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -1,6 +1,7 @@
 <?php
 
 use Drupal\Component\Utility\Crypt;
+use Drupal\Component\Utility\PlainTextOutput;
 use Drupal\Component\Utility\Unicode;
 use Drupal\Core\Asset\AttachedAssetsInterface;
 use Drupal\Core\Cache\Cache;
@@ -918,7 +919,7 @@ function user_mail($key, &$message, $params) {
 
   // @todo fix this
   $token_options = array('langcode' => $langcode, 'callback' => 'user_mail_tokens', 'clear' => TRUE);
-  $message['subject'] .= $token_service->replace($mail_config->get($key . '.subject'), $variables, $token_options);
+  $message['subject'] .= PlainTextOutput::renderFromHtml($token_service->replace($mail_config->get($key . '.subject'), $variables, $token_options));
   $message['body'][] = $token_service->replace($mail_config->get($key . '.body'), $variables, $token_options);
 
   $language_manager->setConfigOverrideLanguage($original_language);
diff --git a/core/tests/Drupal/Tests/Core/Utility/TokenStringTest.php b/core/tests/Drupal/Tests/Core/Utility/TokenStringTest.php
deleted file mode 100644
index c2c7b41..0000000
--- a/core/tests/Drupal/Tests/Core/Utility/TokenStringTest.php
+++ /dev/null
@@ -1,88 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\Tests\Core\Utility\TokenStringTest.
- */
-
-namespace Drupal\Tests\Core\Utility;
-
-use Drupal\Component\Utility\Html;
-use Drupal\Component\Utility\SafeStringInterface;
-use Drupal\Core\Utility\TokenString;
-use Drupal\Tests\UnitTestCase;
-
-/**
- * @coversDefaultClass \Drupal\Core\Utility\TokenString
- * @group Utility
- */
-class TokenStringTest extends UnitTestCase {
-
-  /**
-   * @covers ::__toString
-   * @dataProvider providerTestToString
-   */
-  public function testToString($expected, $input) {
-    $token_string = TokenString::create($input);
-
-    $this->assertEquals($expected, (string) $token_string);
-  }
-
-  /**
-   * @covers ::create
-   */
-  public function testCreateWithEmptyString() {
-    $token_string = TokenString::create('');
-    $this->assertInstanceOf(TokenString::class, $token_string);
-    $this->assertEquals('', $token_string->__toString());
-  }
-
-  /**
-   * @covers ::create
-   */
-  public function testCreateWithSafeString() {
-    $string = '<em class="placeholder">foo</em>';
-    $safe_string = $this->prophesize(SafeStringInterface::class);
-    $safe_string->__toString()->willReturn($string);
-    $safe_string = $safe_string->reveal();
-
-    $token_string = TokenString::create($safe_string);
-    $this->assertInstanceOf(TokenString::class, $token_string);
-    $this->assertEquals(Html::escape($string), $token_string->__toString());
-    $this->assertEquals($string, $token_string->renderToHtml());
-  }
-
-  public function providerTestToString() {
-    $data = [];
-    $data['simple-text'] = ['Foo bar', 'Foo bar'];
-    $string = '<h2>This is html</h2>';
-    $data['html-text'] = [Html::escape($string), $string];
-    $string = '<script>alert(123)</script>';
-    $data['xss-test'] = [Html::escape($string), $string];
-
-    return $data;
-  }
-
-  /**
-   * @covers ::renderToHtml
-   * @dataProvider providerTestRenderToHtml
-   */
-  public function testRenderToHtml($expected, $input) {
-    /** @var \Drupal\Core\Utility\TokenString $token_string */
-    $token_string = TokenString::create($input);
-    $this->assertEquals($expected, $token_string->renderToHtml());
-  }
-
-  public function providerTestRenderToHtml() {
-    $data = [];
-    $data['simple-text'] = ['Foo bar', 'Foo bar'];
-    $string = '<strong>This is html</strong>';
-    $data['html-text'] = [$string, $string];
-    $string = '<script>alert(123)</script>';
-    $data['xss-test'] = ['alert(123)', $string];
-    $data['xss-test2'] = ['<a href="alert(1)">Giraffe</a>', '<a href="javascript:alert(1)">Giraffe</a>'];
-
-    return $data;
-  }
-
-}
diff --git a/core/tests/Drupal/Tests/Core/Utility/TokenTest.php b/core/tests/Drupal/Tests/Core/Utility/TokenTest.php
index a083471..7fd8324 100644
--- a/core/tests/Drupal/Tests/Core/Utility/TokenTest.php
+++ b/core/tests/Drupal/Tests/Core/Utility/TokenTest.php
@@ -278,7 +278,9 @@ public function testReplaceEscaping($string, array $tokens, $expected) {
         return $args[2]['tokens'];
       });
 
-    $this->assertEquals($expected, $this->token->replace($string, ['tokens' => $tokens]));
+    $result = $this->token->replace($string, ['tokens' => $tokens]);
+    $this->assertInternalType('string', $result);
+    $this->assertEquals($expected, $result);
   }
 
   public function providerTestReplaceEscaping() {
@@ -286,74 +288,15 @@ public function providerTestReplaceEscaping() {
 
     // No tokens. The first argument to Token::replace() should not be escaped.
     $data['no-tokens'] = ['muh', [], 'muh'];
-    $data['html-in-string'] = ['<h1>Giraffe</h1>', [], TokenString::create('<h1>Giraffe</h1>')];
-    $data['html-in-string-quote'] = ['<h1>Giraffe"</h1>', [], TokenString::create('<h1>Giraffe"</h1>')];
-
-    // Token escaping.
-    $data['simple-placeholder'] = [
-      '<strong>[token:meh]</strong>',
-      ['[token:meh]' => 'muh'],
-      TokenString::create('<strong>muh</strong>')
-    ];
-    $data['simple-placeholder-with-xss'] = [
-      '<h1>[token:meh]</h1>',
-      ['[token:meh]' => "<script>alert(1)</script>"],
-      TokenString::create('<h1>' . Html::escape('<script>alert(1)</script>') . '</h1>')
-    ];
+    $data['html-in-string'] = ['<h1>Giraffe</h1>', [], '<h1>Giraffe</h1>'];
+    $data['html-in-string-quote'] = ['<h1>Giraffe"</h1>', [], '<h1>Giraffe"</h1>'];
+
+    $data['simple-placeholder-with-plain-text'] = ['<h1>[token:meh]</h1>', ['[token:meh]' => 'Giraffe"'], '<h1>' . Html::escape('Giraffe"') . '</h1>'];
 
     $data['simple-placeholder-with-safe-html'] = [
       '<h1>[token:meh]</h1>',
-      ['[token:meh]' => SafeString::create("<em>Emphasized</em>")],
-      TokenString::create('<h1><em>Emphasized</em></h1>')
-    ];
-
-    return $data;
-  }
-
-  /**
-   * Tests that Token::replace() does not mark its output as safe.
-   *
-   * There are many ways for XSS to be injected into Token::replace(). This
-   * tests some of them and ensures that the result is therefore not a
-   * SafeStringInterface object.
-   *
-   * @covers ::replace
-   * @dataProvider providerTestReplaceUnsafe
-   */
-  public function testReplaceUnsafe($string, array $tokens, $expected, $expected_raw) {
-    $this->moduleHandler->expects($this->any())
-      ->method('invokeAll')
-      ->willReturnCallback(function ($type, $args) {
-        return $args[2]['tokens'];
-      });
-
-    $output = $this->token->replace($string, ['tokens' => $tokens]);
-    $this->assertInstanceOf(TokenString::class, $output);
-    $this->assertEquals($expected, $output);
-    $this->assertEquals($output->renderToHtml(), $expected_raw);
-  }
-
-  public function providerTestReplaceUnsafe() {
-    $data = [];
-
-    // XSS can be injected directly into the first argument.
-    $data['xss-via-string'] = ['<script>alert(1)</script>', [], TokenString::create('<script>alert(1)</script>'), 'alert(1)'];
-
-    // XSS can be injected via "safe" markup injected into an attribute value.
-    $data['xss-via-attribute'] = [
-      '<a title="[token:meh]">Giraffe</a>',
-      ['[token:meh]' => SafeString::create(Xss::filter('" onclick="alert(1)'))],
-      TokenString::create('<a title="" onclick="alert(1)">Giraffe</a>'),
-      '<a title="">Giraffe</a>',
-    ];
-
-    // XSS can be injected via a URL protocol (especially via tokens that don't
-    // filter for URL, such as [comment:title]).
-    $data['xss-via-protocol'] = [
-      '<a href="[token:meh]">Giraffe</a>',
-      ['[token:meh]' => "javascript:alert(1)"],
-      TokenString::create('<a href="javascript:alert(1)">Giraffe</a>'),
-      '<a href="alert(1)">Giraffe</a>',
+      ['[token:meh]' => SafeString::create('<em>Emphasized</em>')],
+      '<h1><em>Emphasized</em></h1>',
     ];
 
     return $data;