Continue IFWL widget cleanup.

xfa/fwl/core/cfwl_pushbutton.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_pushbutton.h"
 
 #include <memory>
 
 #include "third_party/base/ptr_util.h"
 
 CFWL_PushButton::CFWL_PushButton(const IFWL_App* app)
     : CFWL_Widget(app), m_pBitmap(nullptr) {}
 
 CFWL_PushButton::~CFWL_PushButton() {}
 
 void CFWL_PushButton::Initialize() {
   ASSERT(!m_pIface);
 
   m_pIface = pdfium::MakeUnique<IFWL_PushButton>(
       m_pApp, pdfium::MakeUnique<CFWL_WidgetProperties>(this));
 
   CFWL_Widget::Initialize();
 }
 
-FWL_Error CFWL_PushButton::GetCaption(CFX_WideString& wsCaption) {
-  wsCaption = m_wsCaption;
-  return FWL_Error::Succeeded;
-}
-
 FWL_Error CFWL_PushButton::SetCaption(const CFX_WideStringC& wsCaption) {
   m_wsCaption = wsCaption;
   return FWL_Error::Succeeded;
 }
 
 CFX_DIBitmap* CFWL_PushButton::GetPicture() {
   return m_pBitmap;
 }
 
 FWL_Error CFWL_PushButton::SetPicture(CFX_DIBitmap* pBitmap) {
   m_pBitmap = pBitmap;
   return FWL_Error::Succeeded;
 }
 
-FWL_Error CFWL_PushButton::GetCaption(IFWL_Widget* pWidget,
-                                      CFX_WideString& wsCaption) {
+void CFWL_PushButton::GetCaption(IFWL_Widget* pWidget,
+                                 CFX_WideString& wsCaption) {
   wsCaption = m_wsCaption;
-  return FWL_Error::Succeeded;
 }
 
 CFX_DIBitmap* CFWL_PushButton::GetPicture(IFWL_Widget* pWidget) {
   return m_pBitmap;
 }