arc: Add splash screen for ARC++ Kiosk startup

chrome/browser/chromeos/login/existing_user_controller.cc

Index: chrome/browser/chromeos/login/existing_user_controller.cc
diff --git a/chrome/browser/chromeos/login/existing_user_controller.cc b/chrome/browser/chromeos/login/existing_user_controller.cc
index 2df4994d51233e4fc5692c30d346ff2e5e5f7f3a..e830eebc7f0073e835da6cceb2ee08a7edac8657 100644
--- a/chrome/browser/chromeos/login/existing_user_controller.cc
+++ b/chrome/browser/chromeos/login/existing_user_controller.cc
@@ -23,6 +23,7 @@
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/chromeos/boot_times_recorder.h"
 #include "chrome/browser/chromeos/customization/customization_document.h"
+#include "chrome/browser/chromeos/login/arc_kiosk_controller.h"
 #include "chrome/browser/chromeos/login/auth/chrome_login_performer.h"
 #include "chrome/browser/chromeos/login/easy_unlock/bootstrap_user_context_initializer.h"
 #include "chrome/browser/chromeos/login/easy_unlock/bootstrap_user_flow.h"
@@ -922,9 +923,7 @@ void ExistingUserController::LoginAsKioskApp(const std::string& app_id,
 }
 
 void ExistingUserController::LoginAsArcKioskApp(const AccountId& account_id) {
-  login_performer_.reset(nullptr);
-  login_performer_.reset(new ChromeLoginPerformer(this));
-  login_performer_->LoginAsArcKioskAccount(account_id);
+  host_->StartArcKiosk(account_id);
 }
 
 void ExistingUserController::ConfigureAutoLogin() {