Cleanup widget edge related code

xfa/fwl/cfwl_combobox.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/cfwl_combobox.h"
 
 #include <algorithm>
 #include <memory>
@@ skipping 127 matching lines @@
   }
 
   if (!pGraphics)
     return;
   if (!m_pProperties->m_pThemeProvider)
     return;
 
   IFWL_ThemeProvider* pTheme = m_pProperties->m_pThemeProvider;
   if (HasBorder())
     DrawBorder(pGraphics, CFWL_Part::Border, pTheme, pMatrix);
-  if (HasEdge())
-    DrawEdge(pGraphics, CFWL_Part::Edge, pTheme, pMatrix);
 
   if (!IsDropDownStyle()) {
     CFX_RectF rtTextBk(m_rtClient);
     rtTextBk.width -= m_rtBtn.width;
 
     CFWL_ThemeBackground param;
     param.m_pWidget = this;
     param.m_iPart = CFWL_Part::Background;
     param.m_pGraphics = pGraphics;
     if (pMatrix)
@@ skipping 876 matching lines @@
       else
         iCurSel++;
     }
     m_iCurSel = iCurSel;
     SyncEditText(m_iCurSel);
     return;
   }
   if (m_pEdit)
     m_pEdit->GetDelegate()->OnProcessMessage(pMsg);
 }