Cleanup CFWL_Widget code to return CFX_RectFs where appropriate

xfa/fwl/cfwl_datetimeedit.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "xfa/fwl/cfwl_datetimeedit.h"
 
 #include <memory>
 #include <utility>
@@ skipping 35 matching lines @@
       pMouse->m_dwCmd == FWL_MouseCommand::RightButtonDown) {
     if ((m_pProperties->m_dwStates & FWL_WGTSTATE_Focused) == 0)
       m_pProperties->m_dwStates |= FWL_WGTSTATE_Focused;
 
     CFWL_DateTimePicker* pDateTime =
         static_cast<CFWL_DateTimePicker*>(m_pOuter);
     if (pDateTime->IsMonthCalendarVisible()) {
       CFX_RectF rtInvalidate = pDateTime->GetWidgetRect();
       pDateTime->ShowMonthCalendar(false);
       rtInvalidate.Offset(-rtInvalidate.left, -rtInvalidate.top);
-      pDateTime->Repaint(&rtInvalidate);
+      pDateTime->RepaintRect(rtInvalidate);
     }
   }
   CFWL_Edit::OnProcessMessage(pMessage);
 }