Update to Drupal 8.0.0-beta15. For more information, see: https://www.drupal.org/node/2563023

core/misc/drupalSettingsLoader.js

@@ -0,0 +1,24 @@
+/**
+ * @file
+ * Parse inline JSON and initialize the drupalSettings global object.
+ */
+
+(function () {
+
+  "use strict";
+
+  var settingsElement = document.querySelector('script[type="application/json"][data-drupal-selector="drupal-settings-json"]');
+
+  /**
+   * Variable generated by Drupal with all the configuration created from PHP.
+   *
+   * @global
+   *
+   * @type {object}
+   */
+  window.drupalSettings = {};
+
+  if (settingsElement !== null) {
+    window.drupalSettings = JSON.parse(settingsElement.textContent);
+  }
+})();