Cleanup IFWL_Widget visibility and virtual parameters

xfa/fwl/core/ifwl_listbox.h

 // 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
 
 #ifndef XFA_FWL_CORE_IFWL_LISTBOX_H_
 #define XFA_FWL_CORE_IFWL_LISTBOX_H_
 
 #include <memory>
@@ skipping 89 matching lines @@
 
 class IFWL_ListBox : public IFWL_Widget {
  public:
   IFWL_ListBox(const IFWL_App* app,
                std::unique_ptr<CFWL_WidgetProperties> properties,
                IFWL_Widget* pOuter);
   ~IFWL_ListBox() override;
 
   // IFWL_Widget
   FWL_Type GetClassID() const override;
-  FWL_Error GetWidgetRect(CFX_RectF& rect, bool bAutoSize = false) override;
-  FWL_Error Update() override;
+  void GetWidgetRect(CFX_RectF& rect, bool bAutoSize = false) override;
+  void Update() override;
   FWL_WidgetHit HitTest(FX_FLOAT fx, FX_FLOAT fy) override;
-  FWL_Error DrawWidget(CFX_Graphics* pGraphics,
-                       const CFX_Matrix* pMatrix = nullptr) override;
-  FWL_Error SetThemeProvider(IFWL_ThemeProvider* pThemeProvider) override;
+  void DrawWidget(CFX_Graphics* pGraphics,
+                  const CFX_Matrix* pMatrix = nullptr) override;
+  void SetThemeProvider(IFWL_ThemeProvider* pThemeProvider) override;
   void OnProcessMessage(CFWL_Message* pMessage) override;
   void OnProcessEvent(CFWL_Event* pEvent) override;
   void OnDrawWidget(CFX_Graphics* pGraphics,
                     const CFX_Matrix* pMatrix) override;
 
   int32_t CountSelItems();
   CFWL_ListItem* GetSelItem(int32_t nIndexSel);
   int32_t GetSelIndex(int32_t nIndex);
   FWL_Error SetSelItem(CFWL_ListItem* hItem, bool bSelect = true);
   FWL_Error GetItemText(CFWL_ListItem* hItem, CFX_WideString& wsText);
@@ skipping 60 matching lines @@
   void OnLButtonDown(CFWL_MsgMouse* pMsg);
   void OnLButtonUp(CFWL_MsgMouse* pMsg);
   void OnMouseWheel(CFWL_MsgMouseWheel* pMsg);
   void OnKeyDown(CFWL_MsgKey* pMsg);
   void OnVK(CFWL_ListItem* hItem, bool bShift, bool bCtrl);
   bool OnScroll(IFWL_ScrollBar* pScrollBar, uint32_t dwCode, FX_FLOAT fPos);
   void DispatchSelChangedEv();
 };
 
 #endif  // XFA_FWL_CORE_IFWL_LISTBOX_H_