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

ash/system/logout_button/logout_button_tray.h

Index: ash/system/logout_button/logout_button_tray.h
diff --git a/ash/system/logout_button/logout_button_tray.h b/ash/system/logout_button/logout_button_tray.h
index 5683e5e2654c13f52e1d2e9efe0a9403e91b9cf2..8abca7232f7ff4a46c1aa1275673dff8786035cc 100644
--- a/ash/system/logout_button/logout_button_tray.h
+++ b/ash/system/logout_button/logout_button_tray.h
@@ -10,6 +10,8 @@
 #include "ash/system/user/login_status.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
+#include "base/memory/weak_ptr.h"
+#include "base/time/time.h"
 #include "ui/views/controls/button/button.h"
 
 namespace views {
@@ -20,6 +22,7 @@ namespace ash {
 namespace internal {
 
 class StatusAreaWidget;
+class LogoutConfirmationDialogView;
 
 // Adds a logout button to the launcher's status area if enabled by the
 // kShowLogoutButtonInTray pref.
@@ -30,6 +33,9 @@ class LogoutButtonTray : public TrayBackgroundView,
   explicit LogoutButtonTray(StatusAreaWidget* status_area_widget);
   virtual ~LogoutButtonTray();
 
+  void EnsureConfirmationDialogShown();

[bartfab (slow), 2013/10/28 16:24:07]

Nit: I know I suggested the name but I think it can be improved further a little
bit:

EnsureConfirmationDialogIsShowing();

[binjin, 2013/10/29 16:07:05]

Done.

+  void EnsureConfirmationDialogClosed();

[bartfab (slow), 2013/10/28 16:24:07]

Nit: Add "Is" to the name:

EnsureConfirmationDialogIsClosed();

[binjin, 2013/10/29 16:07:05]

Done.

+
   // TrayBackgroundView:
   virtual void SetShelfAlignment(ShelfAlignment alignment) OVERRIDE;
   virtual base::string16 GetAccessibleNameForTray() OVERRIDE;
@@ -39,6 +45,7 @@ class LogoutButtonTray : public TrayBackgroundView,
 
   // LogoutButtonObserver:
   virtual void OnShowLogoutButtonInTrayChanged(bool show) OVERRIDE;
+  virtual void OnLogoutDialogDurationChanged(int duration) OVERRIDE;
 
   // views::ButtonListener:
   virtual void ButtonPressed(views::Button* sender,
@@ -52,6 +59,9 @@ class LogoutButtonTray : public TrayBackgroundView,
   views::LabelButton* button_;  // Not owned.
   user::LoginStatus login_status_;
   bool show_logout_button_in_tray_;
+  base::TimeDelta dialog_duration_;
+
+  base::WeakPtr<LogoutConfirmationDialogView> confirm_dialog_;

[bartfab (slow), 2013/10/28 16:24:07]

Nit: s/confirm_dialog_/confirmation_dialog_/

[binjin, 2013/10/29 16:07:05]

Done.

 
   DISALLOW_COPY_AND_ASSIGN(LogoutButtonTray);
 };