core/lib/Drupal/Core/Render/BubbleableMetadata.php | 182 +++++++++++++++-
 core/lib/Drupal/Core/Render/Renderer.php           |   2 +-
 core/modules/filter/src/Element/ProcessedText.php  |   2 +-
 core/modules/filter/src/FilterProcessResult.php    | 235 +--------------------
 4 files changed, 185 insertions(+), 236 deletions(-)

diff --git a/core/lib/Drupal/Core/Render/BubbleableMetadata.php b/core/lib/Drupal/Core/Render/BubbleableMetadata.php
index 467e02c..7a6ab56 100644
--- a/core/lib/Drupal/Core/Render/BubbleableMetadata.php
+++ b/core/lib/Drupal/Core/Render/BubbleableMetadata.php
@@ -59,14 +59,19 @@ class BubbleableMetadata {
    *   An array of cache contexts.
    * @param string[] $tags
    *   An array of cache tags.
-   * @param int[] $max_age
+   * @param int $max_age
    *   Cache max-age, in seconds. Cache::PERMANENT to cache forever.
    * @param array $attached
    *   An array of attached assets.
    * @param array $post_render_cache
    *   An array of #post_render_cache metadata.
+   *
+   * @throws \InvalidArgumentException
    */
   public function __construct(array $contexts = [], array $tags = [], $max_age = Cache::PERMANENT, array $attached = [], array $post_render_cache = []) {
+    if (!is_int($max_age)) {
+      throw new \InvalidArgumentException('$max_age must be an integer');
+    }
     $this->contexts = $contexts;
     $this->tags = $tags;
     $this->maxAge = $max_age;
@@ -129,4 +134,179 @@ public static function createFromRenderArray(array $build) {
     return $meta;
   }
 
+  /**
+   * Gets cache tags.
+   *
+   * @return string[]
+   */
+  public function getCacheTags() {
+    return $this->tags;
+  }
+
+  /**
+   * Adds cache tags.
+   *
+   * @param string[] $cache_tags
+   *   The cache tags to be added.
+   *
+   * @return $this
+   */
+  public function addCacheTags(array $cache_tags) {
+    $this->tags = Cache::mergeTags($this->tags, $cache_tags);
+    return $this;
+  }
+
+  /**
+   * Sets cache tags.
+   *
+   * @param string[] $cache_tags
+   *   The cache tags to be associated.
+   *
+   * @return $this
+   */
+  public function setCacheTags(array $cache_tags) {
+    $this->tags = $cache_tags;
+    return $this;
+  }
+
+  /**
+   * Gets cache contexts.
+   *
+   * @return string[]
+   */
+  public function getCacheContexts() {
+    return $this->contexts;
+  }
+
+  /**
+   * Adds cache contexts.
+   *
+   * @param string[] $cache_contexts
+   *   The cache contexts to be added.
+   *
+   * @return $this
+   */
+  public function addCacheContexts(array $cache_contexts) {
+    $this->contexts = Cache::mergeContexts($this->contexts, $cache_contexts);
+    return $this;
+  }
+
+  /**
+   * Sets cache contexts.
+   *
+   * @param string[] $cache_contexts
+   *   The cache contexts to be associated.
+   *
+   * @return $this
+   */
+  public function setCacheContexts(array $cache_contexts) {
+    $this->cacheContexts = $cache_contexts;
+    return $this;
+  }
+
+  /**
+   * Gets the maximum age (in seconds).
+   *
+   * @return int
+   */
+  public function getCacheMaxAge() {
+    return $this->maxAge;
+  }
+
+  /**
+   * Sets the maximum age (in seconds).
+   *
+   * Defaults to Cache::PERMANENT
+   *
+   * @param int $max_age
+   *   The max age to associate.
+   *
+   * @return $this
+   *
+   * @throws \InvalidArgumentException
+   */
+  public function setCacheMaxAge($max_age) {
+    if (!is_int($max_age)) {
+      throw new \InvalidArgumentException('$max_age must be an integer');
+    }
+
+    $this->maxAge = $max_age;
+    return $this;
+  }
+
+  /**
+   * Gets assets.
+   *
+   * @return array
+   */
+  public function getAssets() {
+    return $this->attached;
+  }
+
+  /**
+   * Adds assets.
+   *
+   * @param array $assets
+   *   The associated assets to be attached.
+   *
+   * @return $this
+   */
+  public function addAssets(array $assets) {
+    $this->attached = NestedArray::mergeDeep($this->attached, $assets);
+    return $this;
+  }
+
+  /**
+   * Sets assets.
+   *
+   * @param array $assets
+   *   The associated assets to be attached.
+   *
+   * @return $this
+   */
+  public function setAssets(array $assets) {
+    $this->attached = $assets;
+    return $this;
+  }
+
+  /**
+   * Gets #post_render_cache callbacks.
+   *
+   * @return array
+   */
+  public function getPostRenderCacheCallbacks() {
+    return $this->postRenderCache;
+  }
+
+  /**
+   * Adds #post_render_cache callbacks.
+   *
+   * @param string $callback
+   *   The #post_render_cache callback that will replace the placeholder with
+   *   its eventual markup.
+   * @param array $context
+   *   An array providing context for the #post_render_cache callback.
+   *
+   * @see \Drupal\Core\Render\RendererInterface::generateCachePlaceholder()
+   *
+   * @return $this
+   */
+  public function addPostRenderCacheCallback($callback, array $context) {
+    $this->postRenderCache[$callback][] = $context;
+    return $this;
+  }
+
+  /**
+   * Sets #post_render_cache callbacks.
+   *
+   * @param array $post_render_cache_callbacks
+   *   The associated #post_render_cache callbacks to be executed.
+   *
+   * @return $this
+   */
+  public function setPostRenderCacheCallbacks(array $post_render_cache_callbacks) {
+    $this->postRenderCache = $post_render_cache_callbacks;
+    return $this;
+  }
+
 }
diff --git a/core/lib/Drupal/Core/Render/Renderer.php b/core/lib/Drupal/Core/Render/Renderer.php
index 5c0c915..860a2e9 100644
--- a/core/lib/Drupal/Core/Render/Renderer.php
+++ b/core/lib/Drupal/Core/Render/Renderer.php
@@ -730,7 +730,7 @@ protected function cacheSet(array &$elements, $pre_bubbling_cid) {
    */
   protected function createCacheID(array $elements) {
     // If the maximum age is zero, then caching is effectively prohibited.
-    if ($elements['#cache']['max-age'] === 0) {
+    if (!empty($elements['#cache']['max-age'])) {
       return FALSE;
     }
 
diff --git a/core/modules/filter/src/Element/ProcessedText.php b/core/modules/filter/src/Element/ProcessedText.php
index 52f0649..d007b5f 100644
--- a/core/modules/filter/src/Element/ProcessedText.php
+++ b/core/modules/filter/src/Element/ProcessedText.php
@@ -113,7 +113,7 @@ public static function preRenderText($element) {
     foreach ($filters as $filter) {
       if ($filter_must_be_applied($filter)) {
         $result = $filter->process($text, $langcode);
-        $metadata = $metadata->merge($result->getBubbleableMetadata());
+        $metadata = $metadata->merge($result);
         $text = $result->getProcessedText();
       }
     }
diff --git a/core/modules/filter/src/FilterProcessResult.php b/core/modules/filter/src/FilterProcessResult.php
index d3aeade..548faea 100644
--- a/core/modules/filter/src/FilterProcessResult.php
+++ b/core/modules/filter/src/FilterProcessResult.php
@@ -65,7 +65,7 @@
  * }
  * @endcode
  */
-class FilterProcessResult {
+class FilterProcessResult extends BubbleableMetadata {
 
   /**
    * The processed text.
@@ -77,60 +77,14 @@ class FilterProcessResult {
   protected $processedText;
 
   /**
-   * An array of associated assets to be attached.
-   *
-   * @see drupal_process_attached()
-   *
-   * @var array
-   */
-  protected $assets;
-
-  /**
-   * The attached cache tags.
-   *
-   * @see drupal_render_collect_cache_tags()
-   *
-   * @var array
-   */
-  protected $cacheTags;
-
-  /**
-   * The associated cache contexts.
-   *
-   * @var string[]
-   */
-  protected $cacheContexts;
-
-  /**
-   * The maximum age.
-   *
-   * @var int
-   */
-  protected $cacheMaxAge;
-
-  /**
-   * The associated #post_render_cache callbacks.
-   *
-   * @see _drupal_render_process_post_render_cache()
-   *
-   * @var array
-   */
-  protected $postRenderCacheCallbacks;
-
-  /**
    * Constructs a FilterProcessResult object.
    *
    * @param string $processed_text
    *   The text as processed by a text filter.
    */
   public function __construct($processed_text) {
+    parent::__construct();
     $this->processedText = $processed_text;
-
-    $this->assets = array();
-    $this->cacheTags = array();
-    $this->cacheContexts = array();
-    $this->cacheMaxAge = Cache::PERMANENT;
-    $this->postRenderCacheCallbacks = array();
   }
 
   /**
@@ -163,189 +117,4 @@ public function setProcessedText($processed_text) {
     $this->processedText = $processed_text;
     return $this;
   }
-
-  /**
-   * Gets cache tags associated with the processed text.
-   *
-   * @return array
-   */
-  public function getCacheTags() {
-    return $this->cacheTags;
-  }
-
-  /**
-   * Adds cache tags associated with the processed text.
-   *
-   * @param array $cache_tags
-   *   The cache tags to be added.
-   *
-   * @return $this
-   */
-  public function addCacheTags(array $cache_tags) {
-    $this->cacheTags = Cache::mergeTags($this->cacheTags, $cache_tags);
-    return $this;
-  }
-
-  /**
-   * Sets cache tags associated with the processed text.
-   *
-   * @param array $cache_tags
-   *   The cache tags to be associated.
-   *
-   * @return $this
-   */
-  public function setCacheTags(array $cache_tags) {
-    $this->cacheTags = $cache_tags;
-    return $this;
-  }
-
-  /**
-   * Gets cache contexts associated with the processed text.
-   *
-   * @return string[]
-   */
-  public function getCacheContexts() {
-    return $this->cacheContexts;
-  }
-
-  /**
-   * Adds cache contexts associated with the processed text.
-   *
-   * @param string[] $cache_contexts
-   *   The cache contexts to be added.
-   *
-   * @return $this
-   */
-  public function addCacheContexts(array $cache_contexts) {
-    $this->cacheContexts = Cache::mergeContexts($this->cacheContexts, $cache_contexts);
-    return $this;
-  }
-
-  /**
-   * Sets cache contexts associated with the processed text.
-   *
-   * @param string[] $cache_contexts
-   *   The cache contexts to be associated.
-   *
-   * @return $this
-   */
-  public function setCacheContexts(array $cache_contexts) {
-    $this->cacheContexts = $cache_contexts;
-    return $this;
-  }
-
-  /**
-   * Gets the maximum age (in seconds) associated with the processed text.
-   *
-   * @return int
-   */
-  public function getCacheMaxAge() {
-    return $this->cacheMaxAge;
-  }
-
-  /**
-   * Sets the maximum age (in seconds) associated with the processed text.
-   *
-   * Defaults to Cache::PERMANENT
-   *
-   * @param int $max_age
-   *   The max age to associate.
-   *
-   * @return $this
-   */
-  public function setCacheMaxAge($max_age) {
-    $this->cacheMaxAge = $max_age;
-    return $this;
-  }
-
-  /**
-   * Gets assets associated with the processed text.
-   *
-   * @return array
-   */
-  public function getAssets() {
-    return $this->assets;
-  }
-
-  /**
-   * Adds assets associated with the processed text.
-   *
-   * @param array $assets
-   *   The associated assets to be attached.
-   *
-   * @return $this
-   */
-  public function addAssets(array $assets) {
-    $this->assets = NestedArray::mergeDeep($this->assets, $assets);
-    return $this;
-  }
-
-  /**
-   * Sets assets associated with the processed text.
-   *
-   * @param array $assets
-   *   The associated assets to be attached.
-   *
-   * @return $this
-   */
-  public function setAssets(array $assets) {
-    $this->assets = $assets;
-    return $this;
-  }
-
-  /**
-   * Gets #post_render_cache callbacks associated with the processed text.
-   *
-   * @return array
-   */
-  public function getPostRenderCacheCallbacks() {
-    return $this->postRenderCacheCallbacks;
-  }
-
-  /**
-   * Adds #post_render_cache callbacks associated with the processed text.
-   *
-   * @param string $callback
-   *   The #post_render_cache callback that will replace the placeholder with
-   *   its eventual markup.
-   * @param array $context
-   *   An array providing context for the #post_render_cache callback.
-   *
-   * @see drupal_render_cache_generate_placeholder()
-   *
-   * @return $this
-   */
-  public function addPostRenderCacheCallback($callback, array $context) {
-    $this->postRenderCacheCallbacks[$callback][] = $context;
-    return $this;
-  }
-
-  /**
-   * Sets #post_render_cache callbacks associated with the processed text.
-   *
-   * @param array $post_render_cache_callbacks
-   *   The associated #post_render_cache callbacks to be executed.
-   *
-   * @return $this
-   */
-  public function setPostRenderCacheCallbacks(array $post_render_cache_callbacks) {
-    $this->postRenderCacheCallbacks = $post_render_cache_callbacks;
-    return $this;
-  }
-
-  /**
-   * Returns the attached asset libraries, etc. as a bubbleable metadata object.
-   *
-   * @return \Drupal\Core\Render\BubbleableMetadata
-   */
-  public function getBubbleableMetadata() {
-    return new BubbleableMetadata(
-      $this->getCacheContexts(),
-      $this->getCacheTags(),
-      $this->getCacheMaxAge(),
-      $this->getAssets(),
-      $this->getPostRenderCacheCallbacks()
-    );
-  }
-
 }