VrShell background implemented in JS.

chrome/browser/resources/vr_shell/vr_shell_ui_scene.js

Index: chrome/browser/resources/vr_shell/vr_shell_ui_scene.js
diff --git a/chrome/browser/resources/vr_shell/vr_shell_ui_scene.js b/chrome/browser/resources/vr_shell/vr_shell_ui_scene.js
index 00182e1162d1eb4a62270e15f5b5fd19a58a4b64..214f66d3a6787be76f45295e415bce17fb5f061c 100644
--- a/chrome/browser/resources/vr_shell/vr_shell_ui_scene.js
+++ b/chrome/browser/resources/vr_shell/vr_shell_ui_scene.js
@@ -63,8 +63,8 @@ scene.Scene = class {
   }
 
   /**
-   * 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++;