Kill dead IFWL_*::Initialize() variants dead.

xfa/include/fwl/basewidget/fwl_scrollbar.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 _FWL_SCROLLBAR_H
 #define _FWL_SCROLLBAR_H
 class CFWL_WidgetImpProperties;
 class IFWL_Widget;
@@ skipping 30 matching lines @@
   FWL_SCBCODE_StepBackward,
   FWL_SCBCODE_StepForward,
   FWL_SCBCODE_Pos,
   FWL_SCBCODE_TrackPos,
   FWL_SCBCODE_EndScroll,
 };
 class IFWL_ScrollBarDP : public IFWL_DataProvider {};
 class IFWL_ScrollBar : public IFWL_Widget {
  public:
   static IFWL_ScrollBar* Create();
-
-  FWL_ERR Initialize(IFWL_Widget* pOuter = NULL);
   FWL_ERR Initialize(const CFWL_WidgetImpProperties& properties,
-                     IFWL_Widget* pOuter = NULL);
+                     IFWL_Widget* pOuter);
   FX_BOOL IsVertical();
   FWL_ERR GetRange(FX_FLOAT& fMin, FX_FLOAT& fMax);
   FWL_ERR SetRange(FX_FLOAT fMin, FX_FLOAT fMax);
   FX_FLOAT GetPageSize();
   FWL_ERR SetPageSize(FX_FLOAT fPageSize);
   FX_FLOAT GetStepSize();
   FWL_ERR SetStepSize(FX_FLOAT fStepSize);
   FX_FLOAT GetPos();
   FWL_ERR SetPos(FX_FLOAT fPos);
   FX_FLOAT GetTrackPos();
   FWL_ERR SetTrackPos(FX_FLOAT fTrackPos);
   FX_BOOL DoScroll(FX_DWORD dwCode, FX_FLOAT fPos = 0.0f);
 
  protected:
   IFWL_ScrollBar();
 };
 #endif