Draft: 3512070: Initial commit to support Drupal internal page cache.

src/Plugin/LanguageNegotiation/LanguageNegotiationCookie.php

@@ -79,12 +79,6 @@ class LanguageNegotiationCookie extends LanguageNegotiationMethodBase implements
 
     if ($request->cookies->has($param) && in_array($request->cookies->get($param), array_keys($this->languageManager->getLanguages()))) {
       $langcode = $request->cookies->get($param);
-
-      // Internal page cache with multiple languages and browser negotiation
-      // could lead to wrong cached sites. Therefore disabling the internal page
-      // cache.
-      // @todo Solve more elegantly in https://www.drupal.org/node/2430335.
-      $this->pageCacheKillSwitch->trigger();
     }
 
     return $langcode;