[ios showcase]Configures Resource Bundle and adds Toolbar Coordinator

ios/showcase/core/main.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.
 
 #import <UIKit/UIKit.h>
+
+#include "base/at_exit.h"
 #import "ios/showcase/core/app_delegate.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 int main(int argc, char* argv[]) {
+  // This needs to be stack allocated and live for the lifetime of
+  // the app.
+  base::AtExitManager at_exit;
+
   @autoreleasepool {
     return UIApplicationMain(argc, argv, nil,
                              NSStringFromClass([AppDelegate class]));
   }
 }