arc: Add splash screen for ARC++ Kiosk startup

chrome/browser/chromeos/login/session/user_session_manager.cc

Index: chrome/browser/chromeos/login/session/user_session_manager.cc
diff --git a/chrome/browser/chromeos/login/session/user_session_manager.cc b/chrome/browser/chromeos/login/session/user_session_manager.cc
index 61c3de9feb182e269cc116c0439633da34662e5a..b065b22c4e183986ee9b4b70ab037256704b1dc1 100644
--- a/chrome/browser/chromeos/login/session/user_session_manager.cc
+++ b/chrome/browser/chromeos/login/session/user_session_manager.cc
@@ -1286,8 +1286,10 @@ bool UserSessionManager::InitializeUserSession(Profile* profile) {
   user_manager::UserManager* user_manager = user_manager::UserManager::Get();
 
   // Kiosk apps has their own session initialization pipeline.
-  if (user_manager->IsLoggedInAsKioskApp())
+  if (user_manager->IsLoggedInAsKioskApp() ||
+      user_manager->IsLoggedInAsArcKioskApp()) {
     return false;
+  }
 
   if (start_session_type_ == PRIMARY_USER_SESSION) {
     UserFlow* user_flow = ChromeUserManager::Get()->GetCurrentUserFlow();