Get rid of NULLs in core/

core/fpdfapi/fpdf_page/fpdf_page_doc.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 "core/fpdfapi/fpdf_page/pageint.h"
 
 #include "core/fdrm/crypto/include/fx_crypt.h"
 #include "core/fpdfapi/fpdf_font/cpdf_type1font.h"
@@ skipping 110 matching lines @@
       delete imageData->get();
       delete imageData;
       m_ImageMap.erase(curr_it);
     }
   }
 }
 
 CPDF_Font* CPDF_DocPageData::GetFont(CPDF_Dictionary* pFontDict,
                                      FX_BOOL findOnly) {
   if (!pFontDict) {
-    return NULL;
+    return nullptr;
   }
   if (findOnly) {
     auto it = m_FontMap.find(pFontDict);
     if (it != m_FontMap.end() && it->second->get()) {
       return it->second->AddRef();
     }
     return nullptr;
   }
 
   CPDF_CountedFont* fontData = nullptr;
@@ skipping 285 matching lines @@
   if (image->use_count() == 0) {
     delete image->get();
     delete image;
     m_ImageMap.erase(it);
   }
 }
 
 CPDF_IccProfile* CPDF_DocPageData::GetIccProfile(
     CPDF_Stream* pIccProfileStream) {
   if (!pIccProfileStream)
-    return NULL;
+    return nullptr;
 
   auto it = m_IccProfileMap.find(pIccProfileStream);
   if (it != m_IccProfileMap.end()) {
     return it->second->AddRef();
   }
 
   CPDF_StreamAcc stream;
   stream.LoadAllData(pIccProfileStream, FALSE);
   uint8_t digest[20];
   CRYPT_SHA1Generate(stream.GetData(), stream.GetSize(), digest);
@@ skipping 83 matching lines @@
 }
 
 CPDF_CountedPattern* CPDF_DocPageData::FindPatternPtr(
     CPDF_Object* pPatternObj) const {
   if (!pPatternObj)
     return nullptr;
 
   auto it = m_PatternMap.find(pPatternObj);
   return it != m_PatternMap.end() ? it->second : nullptr;
 }