Cleanup IFWL_Widget visibility and virtual parameters

xfa/fwl/core/cfwl_datetimepicker.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/core/cfwl_datetimepicker.h"
 
 #include <memory>
 
@@ skipping 130 matching lines @@
 }
 
 FWL_Error CFWL_DateTimePicker::GetBBox(CFX_RectF& rect) {
   return ToDateTimePicker(GetWidget())->GetBBox(rect);
 }
 
 FWL_Error CFWL_DateTimePicker::SetEditLimit(int32_t nLimit) {
   return ToDateTimePicker(GetWidget())->SetEditLimit(nLimit);
 }
 
-FWL_Error CFWL_DateTimePicker::ModifyEditStylesEx(uint32_t dwStylesExAdded,
-                                                  uint32_t dwStylesExRemoved) {
-  return ToDateTimePicker(GetWidget())
+void CFWL_DateTimePicker::ModifyEditStylesEx(uint32_t dwStylesExAdded,
+                                             uint32_t dwStylesExRemoved) {
+  ToDateTimePicker(GetWidget())
       ->ModifyEditStylesEx(dwStylesExAdded, dwStylesExRemoved);
 }