Revert of Fix the settings button and UMA metrics for the message center

ui/message_center/message_center_tray.h

 // 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 UI_MESSAGE_CENTER_MESSAGE_CENTER_TRAY_H_
 #define UI_MESSAGE_CENTER_MESSAGE_CENTER_TRAY_H_
 
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "base/strings/string16.h"
@@ skipping 59 matching lines @@
   message_center::MessageCenter* message_center() { return message_center_; }
 
   // Overridden from MessageCenterObserver:
   void OnNotificationAdded(const std::string& notification_id) override;
   void OnNotificationRemoved(const std::string& notification_id,
                              bool by_user) override;
   void OnNotificationUpdated(const std::string& notification_id) override;
   void OnNotificationClicked(const std::string& notification_id) override;
   void OnNotificationButtonClicked(const std::string& notification_id,
                                    int button_index) override;
-  void OnNotificationSettingsClicked(bool handled) override;
   void OnNotificationDisplayed(const std::string& notification_id,
                                const DisplaySource source) override;
   void OnQuietModeChanged(bool in_quiet_mode) override;
   void OnBlockingStateChanged(NotificationBlocker* blocker) override;
 
  private:
   void OnMessageCenterChanged();
   void NotifyMessageCenterTrayChanged();
   void HidePopupBubbleInternal();
 
   // |message_center_| is a weak pointer that must live longer than
   // MessageCenterTray.
   message_center::MessageCenter* message_center_;
   bool message_center_visible_;
   bool popups_visible_;
   // |delegate_| is a weak pointer that must live longer than MessageCenterTray.
   MessageCenterTrayDelegate* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(MessageCenterTray);
 };
 
 }  // namespace message_center
 
 #endif  // UI_MESSAGE_CENTER_MESSAGE_CENTER_TRAY_H_