Cleanup IFWL_Widget visibility and virtual parameters

xfa/fwl/core/ifwl_formproxy.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/ifwl_formproxy.h"
 
 #include "third_party/base/ptr_util.h"
 #include "xfa/fwl/core/fwl_noteimp.h"
@@ skipping 10 matching lines @@
   return FWL_Type::FormProxy;
 }
 
 bool IFWL_FormProxy::IsInstance(const CFX_WideStringC& wsClass) const {
   if (wsClass == CFX_WideStringC(FWL_CLASS_FormProxy)) {
     return true;
   }
   return IFWL_Form::IsInstance(wsClass);
 }
 
-FWL_Error IFWL_FormProxy::Update() {
-  return FWL_Error::Succeeded;
-}
+void IFWL_FormProxy::Update() {}
 
-FWL_Error IFWL_FormProxy::DrawWidget(CFX_Graphics* pGraphics,
-                                     const CFX_Matrix* pMatrix) {
-  return FWL_Error::Succeeded;
-}
+void IFWL_FormProxy::DrawWidget(CFX_Graphics* pGraphics,
+                                const CFX_Matrix* pMatrix) {}
 
 void IFWL_FormProxy::OnProcessMessage(CFWL_Message* pMessage) {
   m_pOuter->GetDelegate()->OnProcessMessage(pMessage);
 }