message: Tweak docstring on performance counter viewer
diff: @@ -1049,7 +1049,7 @@ QWidget.
  )");
  virtual QWidget *Widget() = 0;
  - DOCUMENT("Updates the duration column if the selected time unit changes.");
  + DOCUMENT("Updates duration columns if the selected time unit changes.");
  virtual void UpdateDurationColumn() = 0;
  protected:
  