Support modal windows

athena/screen/screen_accelerator_handler.h

Index: athena/screen/screen_accelerator_handler.h
diff --git a/athena/screen/screen_accelerator_handler.h b/athena/screen/screen_accelerator_handler.h
index ab578794afbfa2b1e4bc4251a05f426b808cbd1d..fcde448f7c2a5be9df6806c4fff320eabf97e849 100644
--- a/athena/screen/screen_accelerator_handler.h
+++ b/athena/screen/screen_accelerator_handler.h
@@ -1,6 +1,8 @@
 // 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.
+#ifndef ATHENA_SCREEN_SCREEN_ACCELERATOR_HANDLER_H_
+#define ATHENA_SCREEN_SCREEN_ACCELERATOR_HANDLER_H_
 
 #include "athena/input/public/accelerator_manager.h"
 
@@ -31,3 +33,5 @@ class ScreenAcceleratorHandler : public AcceleratorHandler {
 };
 
 }  // namespace athena
+
+#endif  // ATHENA_SCREEN_SCREEN_ACCELERATOR_HANDLER_H_