Remove the most obvious dead code from message center.

ui/message_center/message_center_tray_delegate.h

Index: ui/message_center/message_center_tray_delegate.h
diff --git a/ui/message_center/message_center_tray_delegate.h b/ui/message_center/message_center_tray_delegate.h
index 3ef35abfa592986ede670859f7546d498a249be2..85b24696e76d3dc7cbcc45a88264c262490ccad2 100644
--- a/ui/message_center/message_center_tray_delegate.h
+++ b/ui/message_center/message_center_tray_delegate.h
@@ -25,10 +25,6 @@ class MESSAGE_CENTER_EXPORT MessageCenterTrayDelegate {
   // Remove the popup bubbles from the UI.
   virtual void HidePopups() = 0;
 
-  // Called when a change to the message center could cause a change to popups
-  // that are currently being displayed.
-  virtual void UpdatePopups() = 0;
-
   // Display the message center containing all undismissed notifications to the
   // user.  Returns true if the center was actually displayed to the user.
   virtual bool ShowMessageCenter() = 0;