arc: Avoid showing browser window in ARC++ Kiosk session

chrome/browser/chromeos/login/users/chrome_user_manager_impl.cc

 // Copyright 2014 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.
 
 #include "chrome/browser/chromeos/login/users/chrome_user_manager_impl.h"
 
 #include <stddef.h>
 
 #include <cstddef>
 #include <set>
@@ skipping 865 matching lines @@
   active_user_ = user;
   active_user_->SetStubImage(
       base::MakeUnique<user_manager::UserImage>(
           *ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
               IDR_PROFILE_PICTURE_LOADING)),
       user_manager::User::USER_IMAGE_INVALID, false);
 
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   command_line->AppendSwitch(chromeos::switches::kEnableArc);
   command_line->AppendSwitch(::switches::kForceAndroidAppMode);
+  command_line->AppendSwitch(::switches::kSilentLaunch);
 
   // Disable window animation since kiosk app runs in a single full screen
   // window and window animation causes start-up janks.
   command_line->AppendSwitch(wm::switches::kWindowAnimationsDisabled);
 }
 
 void ChromeUserManagerImpl::DemoAccountLoggedIn() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   active_user_ =
       user_manager::User::CreateKioskAppUser(user_manager::DemoAccountId());
@@ skipping 461 matching lines @@
       break;
     default:
       NOTREACHED();
       break;
   }
 
   return user;
 }
 
 }  // namespace chromeos