Implements the dialog view for logout button tray in public sessions.

ash/system/logout_button/logout_confirmation_dialog_view.h

Index: ash/system/logout_button/logout_confirmation_dialog_view.h
diff --git a/ash/system/logout_button/logout_confirmation_dialog_view.h b/ash/system/logout_button/logout_confirmation_dialog_view.h
new file mode 100644
index 0000000000000000000000000000000000000000..2bc7a989f201b2c14487bf9dc7886f5c85a3e0e3
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+++ b/ash/system/logout_button/logout_confirmation_dialog_view.h
@@ -0,0 +1,77 @@
+// Copyright (c) 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_SYSTEM_LOGOUT_BUTTON_LOGOUT_CONFIRMATION_DIALOG_VIEW_H_
+#define ASH_SYSTEM_LOGOUT_BUTTON_LOGOUT_CONFIRMATION_DIALOG_VIEW_H_
+
+#include "ash/ash_export.h"
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/time/time.h"
+#include "base/timer/timer.h"
+#include "ui/views/window/dialog_delegate.h"
+
+namespace views {
+class Label;
+}
+
+namespace ash {
+namespace internal {
+
+class LogoutButtonTray;
+
+// This class implements dialog view for logout confirmation.
+class ASH_EXPORT LogoutConfirmationDialogView
+    : public views::DialogDelegateView {
+ public:
+  class ASH_EXPORT Delegate {
+   public:
+    Delegate();
+    virtual ~Delegate();
+
+    virtual void LogoutCurrentUser();
+    virtual base::TimeTicks GetCurrentTime() const;
+    virtual base::TimeDelta GetUpdateInterval() const;

[bartfab (slow), 2013/12/17 13:21:03]

Nit: AFAICT, this is never overridden. Hence, it can be removed from the
Delegate.

[binjin, 2013/12/17 14:58:08]

I prefer to keep GetUpdateInterval() in the delegate, otherwise I had to hard
code the update interval, which looks a bit more ugly to me.

[bartfab (slow), 2013/12/17 15:57:46]

Remember that each method you add to the Delegate interface will increase the
binary size and the runtime of the resulting Chrome binary - ever so slightly,
but it will. You cannot avoid putting a constant somewhere. I see no good reason
to put it in the delegate. You can move the constant away from the code though
by putting it a the top of logout_confirmation_dialog_view.cc, in an anonymous
namespace, e.g.:

namespace {
const int kCountdownUpdateIntervalMs = 1000;  // 1 second.
}  // namespace

[binjin, 2013/12/18 18:13:14]

Done.

+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(Delegate);
+  };
+
+  LogoutConfirmationDialogView(LogoutButtonTray* owner, Delegate* delegate);
+  virtual ~LogoutConfirmationDialogView();
+
+  // views::DialogDelegateView:
+  virtual void DeleteDelegate() OVERRIDE;
+  virtual bool Accept() OVERRIDE;
+  virtual ui::ModalType GetModalType() const OVERRIDE;
+  virtual string16 GetWindowTitle() const OVERRIDE;
+  virtual string16 GetDialogButtonLabel(ui::DialogButton button) const OVERRIDE;
+  virtual void OnClosed() OVERRIDE;
+
+  void Show(base::TimeDelta duration);
+
+  void UpdateDialogDuration(base::TimeDelta duration);
+
+ private:
+  void LogoutCurrentUser();
+  void UpdateCountdown();
+
+  views::Label* text_label_;
+
+  base::TimeTicks countdown_start_time_;
+  base::TimeDelta duration_;
+
+  base::RepeatingTimer<LogoutConfirmationDialogView> timer_;
+
+  LogoutButtonTray* owner_;
+
+  Delegate* delegate_;
+
+  DISALLOW_COPY_AND_ASSIGN(LogoutConfirmationDialogView);
+};
+
+}  // namespace internal
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_LOGOUT_BUTTON_LOGOUT_CONFIRMATION_DIALOG_VIEW_H_