diff --git a/core/tests/Drupal/Tests/Core/Render/RendererBubblingTest.php b/core/tests/Drupal/Tests/Core/Render/RendererBubblingTest.php
index 01e2061..34c988c 100644
--- a/core/tests/Drupal/Tests/Core/Render/RendererBubblingTest.php
+++ b/core/tests/Drupal/Tests/Core/Render/RendererBubblingTest.php
@@ -78,9 +78,8 @@ public function testBubblingWithPrerender($test_element) {
     \Drupal::getContainer()->set('state', $memory_state);
     $this->controllerResolver->expects($this->any())
       ->method('getControllerFromDefinition')
-      ->willReturnCallback(function($callable) {
-        return $callable;
-      });
+      ->willReturnArgument(0);
+
     // Simulate the theme system/Twig: a recursive call to Renderer::render(),
     // just like the theme system or a Twig template would have done.
     $this->themeManager->expects($this->any())
@@ -149,7 +148,7 @@ class BubblingTest {
    * #pre_render callback for testBubblingWithPrerender().
    */
   public static function bubblingPreRender($elements) {
-    $callback = get_class() . '::bubblingPostRenderCache';
+    $callback = __CLASS__ . '::bubblingPostRenderCache';
     $context = [
       'foo' => 'bar',
       'baz' => 'qux',
@@ -178,11 +177,11 @@ public static function bubblingPreRender($elements) {
       ],
       'child_nested_pre_render_uncached' => [
         '#cache' => ['cid' => 'uncached_nested'],
-        '#pre_render' => [get_class() . '::bubblingNestedPreRenderUncached'],
+        '#pre_render' => [__CLASS__ . '::bubblingNestedPreRenderUncached'],
       ],
       'child_nested_pre_render_cached' => [
         '#cache' => ['cid' => 'cached_nested'],
-        '#pre_render' => [get_class() . '::bubblingNestedPreRenderCached'],
+        '#pre_render' => [__CLASS__ . '::bubblingNestedPreRenderCached'],
       ],
     ];
     return $elements;
@@ -209,7 +208,7 @@ public static function bubblingNestedPreRenderCached($elements) {
    * #post_render_cache callback for testBubblingWithPrerender().
    */
   public static function bubblingPostRenderCache(array $element, array $context) {
-    $callback = get_class() . '::bubblingPostRenderCache';
+    $callback = __CLASS__ . '::bubblingPostRenderCache';
     $placeholder = \Drupal::service('renderer')->generateCachePlaceholder($callback, $context);
     $element['#markup'] = str_replace($placeholder, 'Post-render cache!' . $context['foo'] . $context['baz'], $element['#markup']);
     return $element;
diff --git a/core/tests/Drupal/Tests/Core/Render/RendererPostRenderCacheTest.php b/core/tests/Drupal/Tests/Core/Render/RendererPostRenderCacheTest.php
index c6e1402..3fa4d7e 100644
--- a/core/tests/Drupal/Tests/Core/Render/RendererPostRenderCacheTest.php
+++ b/core/tests/Drupal/Tests/Core/Render/RendererPostRenderCacheTest.php
@@ -378,9 +378,9 @@ public function testRenderChildrenPostRenderCacheComplex() {
    * @covers ::doRender
    * @covers ::cacheGet
    * @covers ::processPostRenderCache
-   * @covers ::generateCachePlaceholder
+   * @covers ::generateCachePlaceholderV
    */
-  function testPlaceholder() {
+  public function testPlaceholder() {
     $this->setupMemoryCache();
 
     $context = [
@@ -466,7 +466,7 @@ function testPlaceholder() {
    * Tests child element that uses #post_render_cache but that is rendered via a
    * template.
    */
-  function testChildElementPlaceholder() {
+  public function testChildElementPlaceholder() {
     $this->setupMemoryCache();
     // Simulate the theme system/Twig: a recursive call to Renderer::render(),
     // just like the theme system or a Twig template would have done.
@@ -657,7 +657,7 @@ protected function generatePostRenderCacheWithChildrenTestElement(array $context
   }
 
   /**
-   * @return \PHPUnit_Framework_MockObject_Builder_InvocationMocker
+   * @return \Drupal\Core\Theme\ThemeManagerInterface|\PHPUnit_Framework_MockObject_Builder_InvocationMocker
    */
   protected function setupThemeManagerForDetails() {
     return $this->themeManager->expects($this->any())
diff --git a/core/tests/Drupal/Tests/Core/Render/RendererRecursionTest.php b/core/tests/Drupal/Tests/Core/Render/RendererRecursionTest.php
index e9a4527..7b41128 100644
--- a/core/tests/Drupal/Tests/Core/Render/RendererRecursionTest.php
+++ b/core/tests/Drupal/Tests/Core/Render/RendererRecursionTest.php
@@ -15,7 +15,7 @@
  */
 class RendererRecursionTest extends RendererTestBase {
 
-  protected function setUpRenderPlainComplexElements() {
+  protected function setUpRenderRecursionComplexElements() {
     $complex_child_markup = '<p>Imagine this is a render array for an entity.</p>';
     $parent_markup = '<p>Rendered!</p>';
 
@@ -45,11 +45,13 @@ protected function setUpRenderPlainComplexElements() {
    * ::renderRoot() may not be called inside of another ::renderRoot() call.
    *
    * @covers ::renderRoot
+   * @covers ::render
+   * @covers ::doRender
    *
    * @expectedException \LogicException
    */
-  public function testRenderPlainWithNestedRenderRoot() {
-    list($complex_child_markup, $parent_markup, $complex_child_template) = $this->setUpRenderPlainComplexElements();
+  public function testRenderRecursionWithNestedRenderRoot() {
+    list($complex_child_markup, $parent_markup, $complex_child_template) = $this->setUpRenderRecursionComplexElements();
     $renderer = $this->renderer;
     $this->setUpRequest();
 
@@ -57,14 +59,6 @@ public function testRenderPlainWithNestedRenderRoot() {
     $callable = function () use ($renderer, $complex_child) {
       $renderer->renderRoot($complex_child);
     };
-    $this->controllerResolver->expects($this->any())
-      ->method('getControllerFromDefinition')
-      ->willReturnCallback(function($controller) use ($renderer, $callable) {
-        if ($controller == 'Drupal\Tests\Core\Render\PostRenderCache::callback') {
-          return [new PostRenderCache($renderer), 'callback'];
-        }
-        return $callable;
-      });
 
     $page = [
       'content' => [
@@ -85,9 +79,10 @@ public function testRenderPlainWithNestedRenderRoot() {
    *
    * @covers ::renderRoot
    * @covers ::render
+   * @covers ::doRender
    */
-  public function testRenderPlainWithNestedRender() {
-    list($complex_child_markup, $parent_markup, $complex_child_template) = $this->setUpRenderPlainComplexElements();
+  public function testRenderRecursionWithNestedRender() {
+    list($complex_child_markup, $parent_markup, $complex_child_template) = $this->setUpRenderRecursionComplexElements();
     $renderer = $this->renderer;
     $this->setUpRequest();
 
@@ -98,14 +93,6 @@ public function testRenderPlainWithNestedRender() {
       $this->assertEquals($complex_child_markup, $elements['#markup'], 'Rendered complex child output as expected, without the #post_render_cache callback executed.');
       return $elements;
     };
-    $this->controllerResolver->expects($this->any())
-      ->method('getControllerFromDefinition')
-      ->willReturnCallback(function($controller) use ($renderer, $callable) {
-        if ($controller == 'Drupal\Tests\Core\Render\PostRenderCache::callback') {
-          return [new PostRenderCache($renderer), 'callback'];
-        }
-        return $callable;
-      });
 
     $page = [
       'content' => [
@@ -130,8 +117,8 @@ public function testRenderPlainWithNestedRender() {
    * @covers ::renderRoot
    * @covers ::renderPlain
    */
-  public function testRenderPlainWithNestedRenderPlain() {
-    list($complex_child_markup, $parent_markup, $complex_child_template) = $this->setUpRenderPlainComplexElements();
+  public function testRenderRecursionWithNestedRenderPlain() {
+    list($complex_child_markup, $parent_markup, $complex_child_template) = $this->setUpRenderRecursionComplexElements();
     $renderer = $this->renderer;
     $this->setUpRequest();
 
@@ -142,14 +129,6 @@ public function testRenderPlainWithNestedRenderPlain() {
       $this->assertEquals('<p>overridden</p>', $elements['#markup'], 'Rendered complex child output as expected, with the #post_render_cache callback executed.');
       return $elements;
     };
-    $this->controllerResolver->expects($this->any())
-      ->method('getControllerFromDefinition')
-      ->willReturnCallback(function($controller) use ($renderer, $callable) {
-        if ($controller == 'Drupal\Tests\Core\Render\PostRenderCache::callback') {
-          return [new PostRenderCache($renderer), 'callback'];
-        }
-        return $callable;
-      });
 
     $page = [
       'content' => [