Updates the list of display info in TrayDisplay even if notification is prevented.

ash/system/chromeos/tray_display.h

 // Copyright (c) 2012 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_CHROMEOS_TRAY_DISPLAY_H_
 #define ASH_SYSTEM_CHROMEOS_TRAY_DISPLAY_H_
 
 #include <map>
 
 #include "ash/ash_export.h"
@@ skipping 19 matching lines @@
   virtual ~TrayDisplay();
 
   // Overridden from DisplayControllerObserver:
   virtual void OnDisplayConfigurationChanged() OVERRIDE;
 
  private:
   friend class TrayDisplayTest;
 
   typedef std::map<int64, DisplayInfo> DisplayInfoMap;
 
-  // Checks the current display settings and determine what message should be
-  // shown for notification. Returns true if there's a meaningful change. Note
-  // that it's possible to return true and set |message| to empty, which means
-  // the notification should be removed.
-  bool GetDisplayMessageForNotification(base::string16* message);
+  // Scans the current display info and updates |display_info_|. Sets the
+  // previous data to |old_info| if it's not NULL.
+  void UpdateDisplayInfo(DisplayInfoMap* old_info);
+
+  // Compares the current display settings with |old_info| and determine what
+  // message should be shown for notification. Returns true if there's a
+  // meaningful change. Note that it's possible to return true and set |message|
+  // to empty, which means the notification should be removed.
+  bool GetDisplayMessageForNotification(
+      base::string16* message,
+      const DisplayInfoMap& old_info);
 
   // Overridden from SystemTrayItem.
   virtual views::View* CreateDefaultView(user::LoginStatus status) OVERRIDE;
   virtual void DestroyDefaultView() OVERRIDE;
 
   // Test accessors.
   base::string16 GetDefaultViewMessage();
   base::string16 GetNotificationMessage();
   void CloseNotificationForTest();
   views::View* default_view() { return default_; }
 
   views::View* default_;
   DisplayInfoMap display_info_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayDisplay);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_CHROMEOS_TRAY_DISPLAY_H_