Add ARC++ kiosk menu items and ability to start kiosk session.

chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h

Index: chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h
diff --git a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h
index 97364e9fb4800526afe05b3af3f57876645902ab..c0a95e147f9f36a4ba5500672a9c171b226c7ecc 100644
--- a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h
+++ b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h
@@ -378,6 +378,7 @@ class SigninScreenHandler
   void HandleHardlockPod(const std::string& user_id);
   void HandleLaunchKioskApp(const AccountId& app_account_id,
                             bool diagnostic_mode);
+  void HandleLaunchArcKioskApp(const AccountId& app_account_id);
   void HandleGetPublicSessionKeyboardLayouts(const AccountId& account_id,
                                              const std::string& locale);
   void HandleGetTouchViewState();