Clean up VR Shell mode transitions (and fix potential webvr startup race).

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 107 matching lines @@
       this.configure(0.8, 0, 0);
     }
   };
 
   class Controls {
     constructor(contentQuadId) {
       this.buttons = [];
       let descriptors = [
           ['#back', function() {
             // If we are in cinema mode, revert to standard mode on back press.
-            if (sceneManager.mode == api.Mode.CINEMA) {
+            if (sceneManager.cinemaMode) {
               // TODO(crbug/644511): Send a message back to native to handle
               // switching back to standard mode and out of full screen instead
               // of only changing the mode here.
-              sceneManager.setMode(api.Mode.STANDARD);
+              sceneManager.setMode(sceneManager.mode, sceneManager.menuMode,
+                false /* Cinema Mode */);
             } else {
               api.doAction(api.Action.HISTORY_BACK);
             }
           }],
           ['#reload', function() {
             api.doAction(api.Action.RELOAD);
           }],
           ['#forward', function() {
             api.doAction(api.Action.HISTORY_FORWARD);
           }],
@@ skipping 240 matching lines @@
       let update = new api.UiElementUpdate();
       update.setVisible(visible);
       scene.updateElement(this.domUiElement.uiElementId, update);
       scene.flush();
     }
   };
 
   class SceneManager {
     constructor() {
       this.mode = api.Mode.UNKNOWN;
+      this.menuMode = false;
+      this.cinemaMode = false;
 
       this.contentQuad = new ContentQuad();
       let contentId = this.contentQuad.getElementId();
 
       this.controls = new Controls(contentId);
       this.secureOriginWarnings = new SecureOriginWarnings();
       this.omnibox = new Omnibox(contentId);
     }
 
-    setMode(mode) {
+    setMode(mode, menuMode, cinemaMode) {
       this.mode = mode;
-      this.contentQuad.setEnabled(
-          mode == api.Mode.STANDARD || mode == api.Mode.CINEMA);
-      this.contentQuad.setCinemaMode(mode == api.Mode.CINEMA);
+      this.menuMode = menuMode;
+      this.cinemaMode = cinemaMode;
+
+      this.contentQuad.setEnabled(mode == api.Mode.STANDARD && !menuMode);
+      this.contentQuad.setCinemaMode(cinemaMode);
       // TODO(crbug/643815): Set aspect ratio on content quad when available.
       // TODO(amp): Don't show controls in CINEMA mode once MENU mode lands.
-      this.controls.setEnabled(
-          mode == api.Mode.STANDARD || mode == api.Mode.CINEMA);
-      this.omnibox.setEnabled(
-          mode == api.Mode.STANDARD || mode == api.Mode.CINEMA);
+      this.controls.setEnabled(mode == api.Mode.STANDARD && !menuMode);
+      this.omnibox.setEnabled(mode == api.Mode.STANDARD && !menuMode);
       this.secureOriginWarnings.setEnabled(mode == api.Mode.WEB_VR);
     }
 
     setSecureOrigin(secure) {
       this.secureOriginWarnings.setSecureOrigin(secure);
       this.omnibox.setSecureOrigin(secure);
     }
 
     setReloadUiEnabled(enabled) {
       this.controls.setReloadUiEnabled(enabled);
     }
   };
 
   function initialize() {
     sceneManager = new SceneManager();
     scene.flush();
 
     api.domLoaded();
   }
 
   function command(dict) {
     if ('mode' in dict) {
-      sceneManager.setMode(dict['mode']);
+      sceneManager.setMode(dict['mode'], dict['menuMode'], dict['cinemaMode']);
     }
     if ('secureOrigin' in dict) {
       sceneManager.setSecureOrigin(dict['secureOrigin']);
     }
     if ('enableReloadUi' in dict) {
       sceneManager.setReloadUiEnabled(dict['enableReloadUi']);
     }
     if ('url' in dict) {
       let url = dict['url'];
       sceneManager.omnibox.setURL(url['host'], url['path']);
     }
     if ('loading' in dict) {
       sceneManager.omnibox.setLoading(dict['loading']);
     }
     scene.flush();
   }
 
   return {
     initialize: initialize,
     command: command,
   };
 })();
 
 document.addEventListener('DOMContentLoaded', vrShellUi.initialize);