Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/modules/ckeditor/js/models/Model.js

@@ -0,0 +1,70 @@
+/**
+ * @file
+ * A Backbone Model for the state of a CKEditor toolbar configuration .
+ */
+
+(function (Drupal, Backbone) {
+
+  "use strict";
+
+  /**
+   * Backbone model for the CKEditor toolbar configuration state.
+   *
+   * @constructor
+   *
+   * @augments Backbone.Model
+   */
+  Drupal.ckeditor.Model = Backbone.Model.extend(/** @lends Drupal.ckeditor.Model# */{
+
+    /**
+     * Default values.
+     *
+     * @type {object}
+     */
+    defaults: /** @lends Drupal.ckeditor.Model# */{
+
+      /**
+       * The CKEditor configuration that is being manipulated through the UI.
+       */
+      activeEditorConfig: null,
+
+      /**
+       * The textarea that contains the serialized representation of the active
+       * CKEditor configuration.
+       */
+      $textarea: null,
+
+      /**
+       * Tracks whether the active toolbar DOM structure has been changed. When
+       * true, activeEditorConfig needs to be updated, and when that is updated,
+       * $textarea will also be updated.
+       */
+      isDirty: false,
+
+      /**
+       * The configuration for the hidden CKEditor instance that is used to
+       * build the features metadata.
+       */
+      hiddenEditorConfig: null,
+
+      /**
+       * A hash, keyed by a feature name, that details CKEditor plugin features.
+       */
+      featuresMetadata: null,
+
+      /**
+       * Whether the button group names are currently visible.
+       */
+      groupNamesVisible: false
+    },
+
+    /**
+     * @method
+     */
+    sync: function () {
+      // Push the settings into the textarea.
+      this.get('$textarea').val(JSON.stringify(this.get('activeEditorConfig')));
+    }
+  });
+
+})(Drupal, Backbone);