First cut of JS closure compiler use for VR HTML UI.

chrome/browser/resources/vr_shell/vr_shell_ui.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 vrShellUi = (function() {
   'use strict';
 
   let scene = new ui.Scene();
   let sceneManager;
 
@@ skipping 104 matching lines @@
       this.configure(1, 1, 0.015);
     }
 
     onMouseLeave() {
       this.configure(0.8, 0, 0);
     }
   };
 
   class Controls {
     constructor(contentQuadId) {
+      this.enabled = false;
+      this.reloadUiEnabled = false;
+
       this.buttons = [];
       let descriptors = [
           ['#back', function() {
             api.doAction(api.Action.HISTORY_BACK);
           }],
           ['#reload', function() {
             api.doAction(api.Action.RELOAD);
           }],
           ['#forward', function() {
             api.doAction(api.Action.HISTORY_FORWARD);
@@ skipping 25 matching lines @@
       this.reloadUiButton.domElement.addEventListener('click', function() {
         scene.purge();
         api.doAction(api.Action.RELOAD_UI);
       });
 
       let update = new api.UiElementUpdate();
       update.setParentId(contentQuadId);
       update.setVisible(false);
       update.setScale(2.2, 2.2, 1);
       update.setTranslation(0, -0.6, 0.3);
+
+      // The closure compiler should barf on this...
+      update.setTranslation(0, -0.6, 'cat');

[cjgrant, 2016/12/21 17:10:50]

This is what I was playing with:
- If I make a call like this from within vr_shell_ui_api.js, it complains about
type.
- If I break the name of this function, and try calling xSetTranslation(), it
complains (ie. it knows what the update class offers).
- But, this call works fine.

+
       update.setAnchoring(api.XAnchoring.XNONE, api.YAnchoring.YBOTTOM);
       scene.updateElement(this.reloadUiButton.uiElementId, update);
     }
 
     setEnabled(enabled) {
       this.enabled = enabled;
       this.configure();
     }
 
     setReloadUiEnabled(enabled) {
@@ skipping 11 matching lines @@
       update.setVisible(this.enabled && this.reloadUiEnabled);
       scene.updateElement(this.reloadUiButton.uiElementId, update);
     }
   };
 
   class SecureOriginWarnings {
     constructor() {
       /** @const */ var DISTANCE = 0.7;
       /** @const */ var ANGLE_UP = 16.3 * Math.PI / 180.0;
 
+      this.enabled = false;
+      this.secure = false;
+      this.secureOriginTimer = null;
+
       // Permanent WebVR security warning. This warning is shown near the top of
       // the field of view.
       this.webVrSecureWarning = new DomUiElement('#webvr-not-secure-permanent');
       let update = new api.UiElementUpdate();
       update.setScale(DISTANCE, DISTANCE, 1);
       update.setTranslation(0, DISTANCE * Math.sin(ANGLE_UP),
           -DISTANCE * Math.cos(ANGLE_UP));
       update.setRotation(1.0, 0.0, 0.0, ANGLE_UP);
       update.setHitTestable(false);
       update.setVisible(false);
@@ skipping 53 matching lines @@
       scene.updateElement(this.transientWarning.uiElementId, update);
       this.secureOriginTimer = null;
       scene.flush();
     }
   };
 
   class Omnibox {
     constructor(contentQuadId) {
       this.domUiElement = new DomUiElement('#omni-container');
       this.enabled = false;
+      this.loading = false;
       this.level = 0;
       this.visibilityTimeout = 0;
       this.visibilityTimer = null;
+      this.visibleAfterTransition = false;
       this.nativeState = {};
 
       // Initially invisible.
       let update = new api.UiElementUpdate();
       update.setVisible(false);
       scene.updateElement(this.domUiElement.uiElementId, update);
       this.nativeState.visible = false;
 
       // Listen to the end of transitions, so that the box can be natively
       // hidden after it finishes hiding itself.
@@ skipping 189 matching lines @@
     scene.flush();
   }
 
   return {
     initialize: initialize,
     command: command,
   };
 })();
 
 document.addEventListener('DOMContentLoaded', vrShellUi.initialize);