Work around sign compare error from commit be9b894.

xfa/fwl/basewidget/fwl_editimp.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/basewidget/fwl_editimp.h"
 
 #include <algorithm>
 #include <memory>
@@ skipping 761 matching lines @@
   if (!CanRedo())
     return FALSE;
   return Redo(m_DoRecords[++m_iCurRecord].get());
 }
 
 FX_BOOL CFWL_EditImp::CanUndo() {
   return m_iCurRecord >= 0;
 }
 
 FX_BOOL CFWL_EditImp::CanRedo() {
-  return m_iCurRecord < m_DoRecords.size() - 1;
+  int32_t nCount = m_DoRecords.size();
+  return m_iCurRecord < nCount - 1;

[Tom Sepez, 2016/05/20 00:09:19]

nit: 

return m_iCurRecord < pdfium::CollectionSize<int>(m_DoRecords);

 }
 
 FWL_Error CFWL_EditImp::SetTabWidth(FX_FLOAT fTabWidth, FX_BOOL bEquidistant) {
   if (!m_pEdtEngine)
     return FWL_Error::Indefinite;
 
   FDE_TXTEDTPARAMS* pParams = m_pEdtEngine->GetEditParams();
   pParams->fTabWidth = fTabWidth;
   pParams->bTabEquidistant = bEquidistant;
   return FWL_Error::Succeeded;
@@ skipping 1393 matching lines @@
     }
     CFX_RectF rect;
     m_pOwner->GetWidgetRect(rect);
     CFX_RectF rtInvalidate;
     rtInvalidate.Set(0, 0, rect.width + 2, rect.height + 2);
     m_pOwner->Repaint(&rtInvalidate);
   }
   return TRUE;
 }
 void CFWL_EditImpDelegate::DoCursor(CFWL_MsgMouse* pMsg) {}