VrShell background implemented in JS.

chrome/browser/resources/vr_shell/vr_shell_ui_scene.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 var scene = {};
 
 /**
  * The scene class assists in managing element and animations in the UI.  It
  * allows UI update API commands to be queued in batches, and manages allocation
  * of element and animation IDs.
@@ skipping 45 matching lines @@
 
   /**
    * Flush all queued commands to native.
    */
   flush() {
     api.sendCommands(this.commands);
     this.commands = [];
   }
 
   /**
-   * Add a new UiElement to the scene, returning the ID assigned.
-   * @param {api.UiElement} element
+   * Add a new UiElementUpdate to the scene, returning the ID assigned.
+   * @param {api.UiElementUpdate} element
    */
   addElement(element) {
     var id = this.idIndex++;
     element.setId(id);
     this.commands.push(
         {'type': api.Command.ADD_ELEMENT, 'data': element.properties});
     this.elements.add(id);
     return id;
   }
 
@@ skipping 60 matching lines @@
       var id = parseInt(id_key, 10);
       this.removeAnimation(id);
     }
     var ids = this.elements.values();
     for (let id of ids) {
       this.removeElement(id);
     }
     this.flush();
   }
 };