Implement a means of letting native VR Shell control the HTML UI.

chrome/browser/resources/vr_shell/vr_shell_ui.js

Index: chrome/browser/resources/vr_shell/vr_shell_ui.js
diff --git a/chrome/browser/resources/vr_shell/vr_shell_ui.js b/chrome/browser/resources/vr_shell/vr_shell_ui.js
index bafc81153efca8ba01584a4cfba8fd5c3107d921..36e1a057b962c878b1a1725874a772102cbe4e88 100644
--- a/chrome/browser/resources/vr_shell/vr_shell_ui.js
+++ b/chrome/browser/resources/vr_shell/vr_shell_ui.js
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-var vrShellUi = (function() {
+cr.define('chrome.vrShellUi', function() {

[bshe, 2016/10/19 21:02:40]

now that you have cr.js, perhaps do the same for vr_shell_ui_api and
vr_shell_ui_scene?

[cjgrant, 2016/10/20 15:25:39]

Why do that if native is calling only to the UI?  We don't need to expose
api/scene stuff to native, as they are helper libraries for the UI.  Let me know
if I'm missing something.

[bshe, 2016/10/20 18:07:48]

I don't think it is related to native. I believe cr.define is just a helper to
define a namespace. So you don't need to chrome= {} an dchrome.vrShellUi = {}.
It would be nice to have all the js under the same namespace to avoid potential
conflict. Although unlikely this is going to happen. So if you prefer to leave
it this way, I am fine.
I am fine.

[cjgrant, 2016/10/20 19:59:58]

As discussed, removed use of cr.define().

   'use strict';
 
   var scene = new ui.Scene();
@@ -112,9 +112,13 @@ var vrShellUi = (function() {
     api.domLoaded();
   }
 
+  function command(dict) {

[mthiesse, 2016/10/19 18:04:10]

Put in a TODO to implement this?

+  }
+
   return {
     initialize: initialize,
+    command: command,
   };
-})();
+});
 
-document.addEventListener('DOMContentLoaded', vrShellUi.initialize);
+document.addEventListener('DOMContentLoaded', chrome.vrShellUi.initialize);