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diff --git a/chromium/ash/accelerators/exit_warning_handler.h b/chromium/ash/accelerators/exit_warning_handler.h
new file mode 100644
index 00000000000..b99681cb435
--- /dev/null
+++ b/chromium/ash/accelerators/exit_warning_handler.h
@@ -0,0 +1,87 @@
+// Copyright 2013 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 ASH_ACCELERATORS_EXIT_WARNING_HANDLER_H_
+#define ASH_ACCELERATORS_EXIT_WARNING_HANDLER_H_
+
+#include "ash/ash_export.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/timer/timer.h"
+#include "ui/base/accelerators/accelerator.h"
+
+namespace views {
+class Widget;
+}
+
+namespace ash {
+
+// In order to avoid accidental exits when the user presses the exit
+// shortcut by mistake, we require the user press it twice within a
+// period of time. During that time we show a popup informing the
+// user of this.
+//
+// Notes:
+//
+// The corresponding accelerator must be non-repeatable (see
+// kNonrepeatableActions in accelerator_table.cc). Otherwise the "Double Press
+// Exit" will be activated just by holding it down, i.e. probably every time.
+//
+// State Transition Diagrams:
+//
+//  IDLE
+//   | Press
+//  WAIT_FOR_DOUBLE_PRESS action: show ui & start timers
+//   | Press (before time limit )
+//  EXITING action: hide ui, stop timer, exit
+//
+//  IDLE
+//   | Press
+//  WAIT_FOR_DOUBLE_PRESS action: show ui & start timers
+//   | T timer expires
+//  IDLE action: hide ui
+//
+
+class AcceleratorControllerTest;
+
+class ASH_EXPORT ExitWarningHandler {
+ public:
+  ExitWarningHandler();
+
+  ~ExitWarningHandler();
+
+  // Handles accelerator for exit (Ctrl-Shift-Q).
+  void HandleAccelerator();
+
+ private:
+  friend class AcceleratorControllerTest;
+
+  enum State {
+    IDLE,
+    WAIT_FOR_DOUBLE_PRESS,
+    EXITING
+  };
+
+  // Performs actions when the time limit is exceeded.
+  void TimerAction();
+
+  void StartTimer();
+  void CancelTimer();
+
+  void Show();
+  void Hide();
+
+  State state_;
+  scoped_ptr<views::Widget> widget_;
+  base::OneShotTimer<ExitWarningHandler> timer_;
+
+  // Flag to suppress starting the timer for testing. For test we call
+  // TimerAction() directly to simulate the expiration of the timer.
+  bool stub_timer_for_test_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExitWarningHandler);
+};
+
+}  // namespace ash
+
+#endif  // ASH_ACCELERATORS_EXIT_WARNING_HANDLER_H_