Convert FWL_ERR into an enum class.

xfa/fxfa/app/xfa_fffield.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/fxfa/app/xfa_fffield.h"
 
 #include "xfa/fwl/basewidget/ifwl_edit.h"
 #include "xfa/fwl/core/cfwl_message.h"
@@ skipping 767 matching lines @@
 }
 FX_BOOL CXFA_FFField::CommitData() {
   return FALSE;
 }
 FX_BOOL CXFA_FFField::IsDataChanged() {
   return FALSE;
 }
 void CXFA_FFField::TranslateFWLMessage(CFWL_Message* pMessage) {
   GetApp()->GetWidgetMgrDelegate()->OnProcessMessageToForm(pMessage);
 }
-int32_t CXFA_FFField::OnProcessMessage(CFWL_Message* pMessage) {
-  return FWL_ERR_Succeeded;
-}
+void CXFA_FFField::OnProcessMessage(CFWL_Message* pMessage) {}
 
-FWL_ERR CXFA_FFField::OnProcessEvent(CFWL_Event* pEvent) {
+void CXFA_FFField::OnProcessEvent(CFWL_Event* pEvent) {
   switch (pEvent->GetClassID()) {
     case CFWL_EventType::Mouse: {
       CFWL_EvtMouse* event = (CFWL_EvtMouse*)pEvent;
       if (event->m_dwCmd == FWL_MouseCommand::Enter) {
         CXFA_EventParam eParam;
         eParam.m_eType = XFA_EVENT_MouseEnter;
         eParam.m_pTarget = m_pDataAcc;
         m_pDataAcc->ProcessEvent(XFA_ATTRIBUTEENUM_MouseEnter, &eParam);
       } else if (event->m_dwCmd == FWL_MouseCommand::Leave) {
         CXFA_EventParam eParam;
@@ skipping 16 matching lines @@
     case CFWL_EventType::Click: {
       CXFA_EventParam eParam;
       eParam.m_eType = XFA_EVENT_Click;
       eParam.m_pTarget = m_pDataAcc;
       m_pDataAcc->ProcessEvent(XFA_ATTRIBUTEENUM_Click, &eParam);
       break;
     }
     default:
       break;
   }
-  return FWL_ERR_Succeeded;
 }
 
-FWL_ERR CXFA_FFField::OnDrawWidget(CFX_Graphics* pGraphics,
-                                   const CFX_Matrix* pMatrix) {
-  return FWL_ERR_Succeeded;
-}
+void CXFA_FFField::OnDrawWidget(CFX_Graphics* pGraphics,
+                                const CFX_Matrix* pMatrix) {}