.../Core/Ajax/AjaxResponseAttachmentsProcessor.php | 19 +++++++++----------
 .../Render/HtmlResponseAttachmentsProcessor.php    | 22 ++++++----------------
 core/modules/big_pipe/src/Render/BigPipe.php       | 18 +++++++++++++++++-
 3 files changed, 32 insertions(+), 27 deletions(-)

diff --git a/core/lib/Drupal/Core/Ajax/AjaxResponseAttachmentsProcessor.php b/core/lib/Drupal/Core/Ajax/AjaxResponseAttachmentsProcessor.php
index 80bc7f9..7d36b51 100644
--- a/core/lib/Drupal/Core/Ajax/AjaxResponseAttachmentsProcessor.php
+++ b/core/lib/Drupal/Core/Ajax/AjaxResponseAttachmentsProcessor.php
@@ -105,19 +105,16 @@ public function __construct(AssetResolverInterface $asset_resolver, ConfigFactor
   /**
    * {@inheritdoc}
    */
-  public function processAttachments(AttachmentsInterface $response, $ajax_page_state = NULL) {
+  public function processAttachments(AttachmentsInterface $response) {
     // @todo Convert to assertion once https://www.drupal.org/node/2408013 lands
     if (!$response instanceof AjaxResponse) {
       throw new \InvalidArgumentException('\Drupal\Core\Ajax\AjaxResponse instance expected.');
     }
 
-    if ($response->getContent() == '{}') {
-      if (!isset($ajax_page_state)) {
-        $request = $this->requestStack->getCurrentRequest();
-        $ajax_page_state = $request->request->get('ajax_page_state');
-      }
+    $request = $this->requestStack->getCurrentRequest();
 
-      $response->setData($this->buildAttachmentsCommands($response, $ajax_page_state));
+    if ($response->getContent() == '{}') {
+      $response->setData($this->buildAttachmentsCommands($response, $request));
     }
 
     return $response;
@@ -128,13 +125,15 @@ public function processAttachments(AttachmentsInterface $response, $ajax_page_st
    *
    * @param \Drupal\Core\Ajax\AjaxResponse $response
    *   The AJAX response to update.
-   * @param array $ajax_page_state
-   *   The current ajax page state.
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The request object that the AJAX is responding to.
    *
    * @return array
    *   An array of commands ready to be returned as JSON.
    */
-  protected function buildAttachmentsCommands(AjaxResponse $response, array $ajax_page_state = NULL) {
+  protected function buildAttachmentsCommands(AjaxResponse $response, Request $request) {
+    $ajax_page_state = $request->request->get('ajax_page_state');
+
     // Aggregate CSS/JS if necessary, but only during normal site operation.
     $optimize_css = !defined('MAINTENANCE_MODE') && $this->config->get('css.preprocess');
     $optimize_js = !defined('MAINTENANCE_MODE') && $this->config->get('js.preprocess');
diff --git a/core/lib/Drupal/Core/Render/HtmlResponseAttachmentsProcessor.php b/core/lib/Drupal/Core/Render/HtmlResponseAttachmentsProcessor.php
index 93251b5..d77ce4d 100644
--- a/core/lib/Drupal/Core/Render/HtmlResponseAttachmentsProcessor.php
+++ b/core/lib/Drupal/Core/Render/HtmlResponseAttachmentsProcessor.php
@@ -156,13 +156,7 @@ public function processAttachments(AttachmentsInterface $response) {
       $attachment_placeholders = $attached['html_response_attachment_placeholders'];
       unset($attached['html_response_attachment_placeholders']);
 
-      // Take Ajax page state into account, to allow for something like Turbolinks
-      // to be implemented without altering core.
-      // @see https://github.com/rails/turbolinks/
-      // @todo https://www.drupal.org/node/2497115 - Below line is broken due to ->request.
-      $ajax_page_state = $this->requestStack->getCurrentRequest()->get('ajax_page_state');
-
-      $variables = $this->processAssetLibraries($attached, $attachment_placeholders, $ajax_page_state);
+      $variables = $this->processAssetLibraries($attached, $attachment_placeholders);
 
       // Since we can only replace content in the HTML head section if there's a
       // placeholder for it, we can safely avoid processing the render array if
@@ -266,8 +260,6 @@ protected function renderPlaceholders(HtmlResponse $response) {
    *   The attachments to process.
    * @param array $placeholders
    *   The placeholders that exist in the response.
-   * @param array $ajax_page_state
-   *   (optional) The ajax page state of the page.
    *
    * @return array
    *   An array keyed by asset type, with keys:
@@ -275,10 +267,14 @@ protected function renderPlaceholders(HtmlResponse $response) {
    *     - scripts
    *     - scripts_bottom
    */
-  public function processAssetLibraries(array $attached, array $placeholders, array $ajax_page_state = NULL) {
+  protected function processAssetLibraries(array $attached, array $placeholders) {
     $all_attached = ['#attached' => $attached];
     $assets = AttachedAssets::createFromRenderArray($all_attached);
 
+    // Take Ajax page state into account, to allow for something like Turbolinks
+    // to be implemented without altering core.
+    // @see https://github.com/rails/turbolinks/
+    $ajax_page_state = $this->requestStack->getCurrentRequest()->get('ajax_page_state');
     $assets->setAlreadyLoadedLibraries(isset($ajax_page_state) ? explode(',', $ajax_page_state['libraries']) : []);
 
     $variables = [];
@@ -295,13 +291,7 @@ public function processAssetLibraries(array $attached, array $placeholders, arra
       // Optimize JS if necessary, but only during normal site operation.
       $optimize_js = !defined('MAINTENANCE_MODE') && !\Drupal::state()->get('system.maintenance_mode') && $this->config->get('js.preprocess');
       list($js_assets_header, $js_assets_footer) = $this->assetResolver->getJsAssets($assets, $optimize_js);
-    }
-
-    if (isset($placeholders['scripts'])) {
       $variables['scripts'] = $this->jsCollectionRenderer->render($js_assets_header);
-    }
-
-    if (isset($placeholders['scripts_bottom'])) {
       $variables['scripts_bottom'] = $this->jsCollectionRenderer->render($js_assets_footer);
     }
 
diff --git a/core/modules/big_pipe/src/Render/BigPipe.php b/core/modules/big_pipe/src/Render/BigPipe.php
index d374d0f..78c758c 100644
--- a/core/modules/big_pipe/src/Render/BigPipe.php
+++ b/core/modules/big_pipe/src/Render/BigPipe.php
@@ -12,6 +12,12 @@
 use Drupal\Core\Render\BubbleableMetadata;
 use Drupal\Core\Render\RendererInterface;
 use Drupal\Core\Render\AttachmentsResponseProcessorInterface;
+use Symfony\Component\EventDispatcher\EventDispatcher;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
+use Symfony\Component\HttpKernel\Kernel;
+use Symfony\Component\HttpKernel\KernelEvents;
 
 /**
  * A class that allows sending the main content first, then replace
@@ -173,7 +179,17 @@ public function sendContent($content, $attachments, array $placeholders) {
       $response->addCommand(new ReplaceCommand(sprintf('[data-big-pipe-selector="%s"]', $placeholder), $elements['#markup']));
       $response->setAttachments($elements['#attached']);
 
-      $this->ajaxResponseAttachmentsProcessor->processAttachments($response, $this->ajaxPageState);
+      // @todo Clean up.
+      $request_stack = \Drupal::service('request_stack');
+      $master_request = $request_stack->getMasterRequest();
+      $request = Request::create($master_request->getUri(), $master_request->getMethod(), $master_request->query->all(), $master_request->cookies->all(), array(), $master_request->server->all());
+      $request->headers->set('Accept', 'application/json');
+      $request->request->set('ajax_page_state', $this->ajaxPageState);
+      $request_stack->push($request);
+      $event = new FilterResponseEvent(\Drupal::service('http_kernel.basic'), $request, HttpKernelInterface::SUB_REQUEST, $response);
+      \Drupal::service('event_dispatcher')->dispatch(KernelEvents::RESPONSE, $event);
+      $response = $event->getResponse();
+      $request_stack->pop();
 
       // @todo Filter response.
       $json = $response->getContent();