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

ui/message_center/message_center_impl.cc

Index: ui/message_center/message_center_impl.cc
diff --git a/ui/message_center/message_center_impl.cc b/ui/message_center/message_center_impl.cc
index 982611a8d3ba8b447af4378e5ec3054609f64023..4e90822a60c39912172e7c3b82310b7d8c69c271 100644
--- a/ui/message_center/message_center_impl.cc
+++ b/ui/message_center/message_center_impl.cc
@@ -795,13 +795,10 @@
 void MessageCenterImpl::ClickOnSettingsButton(const std::string& id) {
   scoped_refptr<NotificationDelegate> delegate =
       notification_list_->GetNotificationDelegate(id);
-
-  bool handled_by_delegate = false;
   if (delegate.get())
-    handled_by_delegate = delegate->SettingsClick();
-
+    delegate->SettingsClick();
   for (auto& observer : observer_list_)
-    observer.OnNotificationSettingsClicked(handled_by_delegate);
+    observer.OnNotificationSettingsClicked();
 }
 
 void MessageCenterImpl::MarkSinglePopupAsShown(const std::string& id,