Cleanup IFWL_Widget visibility and virtual parameters

xfa/fwl/core/ifwl_pushbutton.h

Index: xfa/fwl/core/ifwl_pushbutton.h
diff --git a/xfa/fwl/core/ifwl_pushbutton.h b/xfa/fwl/core/ifwl_pushbutton.h
index 94078bbfdce91a20384a220c10ce54f1ee2804d6..6fb81f08117a54a8e244daba8c233cea6013b8da 100644
--- a/xfa/fwl/core/ifwl_pushbutton.h
+++ b/xfa/fwl/core/ifwl_pushbutton.h
@@ -44,11 +44,11 @@ class IFWL_PushButton : public IFWL_Widget {
 
   // IFWL_Widget
   FWL_Type GetClassID() const override;
-  FWL_Error GetWidgetRect(CFX_RectF& rect, bool bAutoSize = false) override;
+  void GetWidgetRect(CFX_RectF& rect, bool bAutoSize = false) override;
   void SetStates(uint32_t dwStates, bool bSet = true) override;
-  FWL_Error Update() override;
-  FWL_Error DrawWidget(CFX_Graphics* pGraphics,
-                       const CFX_Matrix* pMatrix = nullptr) override;
+  void Update() override;
+  void DrawWidget(CFX_Graphics* pGraphics,
+                  const CFX_Matrix* pMatrix = nullptr) override;
   void OnProcessMessage(CFWL_Message* pMessage) override;
   void OnDrawWidget(CFX_Graphics* pGraphics,
                     const CFX_Matrix* pMatrix) override;