Update XFA fpdfsdk to match master

fpdfsdk/src/fsdk_annothandler.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 <algorithm>
 
 #include "../include/fpdfxfa/fpdfxfa_doc.h"
 #include "../include/fpdfxfa/fpdfxfa_util.h"
@@ skipping 103 matching lines @@
   }
 }
 
 IPDFSDK_AnnotHandler* CPDFSDK_AnnotHandlerMgr::GetAnnotHandler(
     CPDFSDK_Annot* pAnnot) const {
   ASSERT(pAnnot != NULL);
 
   CPDF_Annot* pPDFAnnot = pAnnot->GetPDFAnnot();
   if (pPDFAnnot)
     return GetAnnotHandler(pPDFAnnot->GetSubType());
-  else if (pAnnot->GetXFAWidget())
+  if (pAnnot->GetXFAWidget())
     return GetAnnotHandler(FSDK_XFAWIDGET_TYPENAME);
-  return NULL;
+  return nullptr;
 }
 
 IPDFSDK_AnnotHandler* CPDFSDK_AnnotHandlerMgr::GetAnnotHandler(
     const CFX_ByteString& sType) const {
   auto it = m_mapType2Handler.find(sType);
   return it != m_mapType2Handler.end() ? it->second : nullptr;
 }
 
 void CPDFSDK_AnnotHandlerMgr::Annot_OnDraw(CPDFSDK_PageView* pPageView,
                                            CPDFSDK_Annot* pAnnot,
@@ skipping 1051 matching lines @@
 
 CPDFSDK_Annot* CPDFSDK_AnnotIterator::PrevAnnot() {
   if (m_pos < m_iteratorAnnotList.size())
     return m_iteratorAnnotList[m_iteratorAnnotList.size() - ++m_pos];
   return nullptr;
 }
 
 CPDFSDK_Annot* CPDFSDK_AnnotIterator::Next() {
   return m_bReverse ? PrevAnnot() : NextAnnot();
 }