[CRD iOS] Use UINavigationController for view stack manipulation

remoting/ios/app/app_delegate.mm

 // 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.
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 #import "remoting/ios/app/app_delegate.h"
 
@@ skipping 37 matching lines @@
 
   [[RemotingService SharedInstance].authentication
       authenticateWithAuthorizationCode:authorizationCode];
 
   [self launchRemotingViewController];
   return YES;
 }
 
 - (void)launchRemotingViewController {
   RemotingViewController* vc = [[RemotingViewController alloc] init];
-  self.window.rootViewController = vc;
+  UINavigationController* navController =
+      [[UINavigationController alloc] initWithRootViewController:vc];
+  navController.navigationBarHidden = true;
+  self.window.rootViewController = navController;
   [self.window makeKeyAndVisible];
 }
 
 @end