.../Core/Render/MainContent/SmartCacheHtmlRenderer.php  | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/core/lib/Drupal/Core/Render/MainContent/SmartCacheHtmlRenderer.php b/core/lib/Drupal/Core/Render/MainContent/SmartCacheHtmlRenderer.php
index 3806958..bccd9f6 100644
--- a/core/lib/Drupal/Core/Render/MainContent/SmartCacheHtmlRenderer.php
+++ b/core/lib/Drupal/Core/Render/MainContent/SmartCacheHtmlRenderer.php
@@ -58,19 +58,18 @@ class SmartCacheHtmlRenderer extends HtmlRenderer {
    *   The module handler.
    * @param \Drupal\Core\Render\RendererInterface $renderer
    *   The renderer service.
-   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
-   *   The current route match.
    * @param \Drupal\Core\Cache\CacheContexts $cache_contexts
    *   The cache contexts service.
+   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
+   *   The current route match.
    * @param \Drupal\Core\Cache\CacheBackendInterface $contexts_cache
    *   The Smart Cache contexts cache bin.
    * @param \Drupal\Core\Cache\CacheBackendInterface $html_cache
    *   The Smart Cache #type => html render array cache bin.
    */
-  public function __construct(TitleResolverInterface $title_resolver, PluginManagerInterface $display_variant_manager, EventDispatcherInterface $event_dispatcher, ModuleHandlerInterface $module_handler, RendererInterface $renderer, RouteMatchInterface $route_match, CacheContexts $cache_contexts, CacheBackendInterface $contexts_cache, CacheBackendInterface $html_cache) {
-    parent::__construct($title_resolver, $display_variant_manager, $event_dispatcher, $module_handler, $renderer);
+  public function __construct(TitleResolverInterface $title_resolver, PluginManagerInterface $display_variant_manager, EventDispatcherInterface $event_dispatcher, ModuleHandlerInterface $module_handler, RendererInterface $renderer, CacheContexts $cache_contexts, RouteMatchInterface $route_match, CacheBackendInterface $contexts_cache, CacheBackendInterface $html_cache) {
+    parent::__construct($title_resolver, $display_variant_manager, $event_dispatcher, $module_handler, $renderer, $cache_contexts);
     $this->routeMatch = $route_match;
-    $this->cacheContexts = $cache_contexts;
     $this->smartContextsCache = $contexts_cache;
     $this->smartHtmlCache = $html_cache;
   }
@@ -106,14 +105,13 @@ protected function finish(array $html) {
     $html_cache_tags = [];
     foreach (Element::children($cacheable_html) as $child) {
       $cacheable_html[$child] = $this->renderer->getCacheableRenderArray($cacheable_html[$child]);
-      $cache_contexts = array_unique(array_merge($cache_contexts, $cacheable_html[$child]['#cache']['contexts']));
+      $cache_contexts = Cache::mergeContexts($cache_contexts, $cacheable_html[$child]['#cache']['contexts']);
       $html_cache_tags = Cache::mergeTags($html_cache_tags, $cacheable_html[$child]['#cache']['tags']);
     }
-    sort($cache_contexts);
 
     // @todo Remove this. Work-around to support the deep-render-array-scanning-
     //    dependent logic bartik_preprocess_html() has: it needs to know about
-    //    the presence or absence of certain regoions. That is similar (but less
+    //    the presence or absence of certain regions. That is similar (but less
     ///   bad) to the evil things one could do with hook_page_alter() in D7.
     foreach (Element::children($html['page']) as $page_region) {
       $cacheable_html['page'][$page_region] = ['#preprocess_functions_messing_with_cacheability' => TRUE];
@@ -123,8 +121,7 @@ protected function finish(array $html) {
     // stored cache contexts and the contexts for this request.
     if ($cache_contexts !== $stored_cache_contexts) {
       if (is_array($stored_cache_contexts)) {
-        $cache_contexts = array_merge($cache_contexts, $stored_cache_contexts);
-        sort($cache_contexts);
+        $cache_contexts = Cache::mergeContexts($cache_contexts, $stored_cache_contexts);
       }
       $this->smartContextsCache->set($contexts_cid, $cache_contexts);
     }