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

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 a83ef30ea09ca787a67c6ac658469cb65ab024e5..cc68712292e4810428ed77e331021463e84ca600 100644
--- a/chrome/browser/resources/vr_shell/vr_shell_ui_scene.js
+++ b/chrome/browser/resources/vr_shell/vr_shell_ui_scene.js
@@ -19,7 +19,7 @@ var ui = (function() {
    * el.setSize(buttonWidth, buttonHeight);
    *
    * // Anchor it to the bottom of the content quad.
-   * el.setParentId(api.getContentElementId());
+   * el.setParentId(contentQuadId);
    * el.setAnchoring(api.XAnchoring.XNONE, api.YAnchoring.YBOTTOM);
    *
    * // Place it just below the content quad edge.
@@ -44,7 +44,7 @@ var ui = (function() {
   class Scene {
 
     constructor() {
-      this.idIndex = api.getContentElementId() + 1;
+      this.idIndex = 1;
       this.commands = [];
       this.elements = new Set();
       this.animations = {};
@@ -80,7 +80,7 @@ var ui = (function() {
       update.id = id;
       this.commands.push({
         'type': api.Command.UPDATE_ELEMENT,
-        'data': update
+        'data': update.properties
       });
     }
 
@@ -133,7 +133,7 @@ var ui = (function() {
     purge() {
       var ids = Object.keys(this.animations);
       for (let id_key of ids) {
-        var id = parseInt(id_key);
+        var id = parseInt(id_key, 10);
         this.removeAnimation(id);
       }
       var ids = this.elements.values();