[Merge to M57][Kiosk] Do not allow to exit the fullscreen mode in kiosk mode.

ash/common/wm/maximize_mode/maximize_mode_event_handler.cc

Index: ash/common/wm/maximize_mode/maximize_mode_event_handler.cc
diff --git a/ash/common/wm/maximize_mode/maximize_mode_event_handler.cc b/ash/common/wm/maximize_mode/maximize_mode_event_handler.cc
index 8edb1d0d2d9a7c7a863c67fabc33d723435cd1d3..da7750604e366de378f9b0f94c10931b8bc9abde 100644
--- a/ash/common/wm/maximize_mode/maximize_mode_event_handler.cc
+++ b/ash/common/wm/maximize_mode/maximize_mode_event_handler.cc
@@ -5,6 +5,7 @@
 #include "ash/common/wm/maximize_mode/maximize_mode_event_handler.h"
 
 #include "ash/common/session/session_state_delegate.h"
+#include "ash/common/system/tray/system_tray_delegate.h"
 #include "ash/common/wm/window_state.h"
 #include "ash/common/wm/wm_event.h"
 #include "ash/common/wm_shell.h"
@@ -53,6 +54,15 @@ bool MaximizeModeEventHandler::ToggleFullscreen(const ui::TouchEvent& event) {
     return false;
   }
 
+  // Do not exit fullscreen in kiosk mode.
+  SystemTrayDelegate* system_tray_delegate =
+      WmShell::Get()->system_tray_delegate();
+  if (system_tray_delegate->GetUserLoginStatus() == LoginStatus::KIOSK_APP ||
+      system_tray_delegate->GetUserLoginStatus() ==
+          LoginStatus::ARC_KIOSK_APP) {
+    return false;
+  }
+
   WMEvent toggle_fullscreen(WM_EVENT_TOGGLE_FULLSCREEN);
   window->GetWindowState()->OnWMEvent(&toggle_fullscreen);
   return true;