Split off IPDF_CryptoHandler into its own .cpp/.h files

core/src/fpdfapi/fpdf_parser/cpdf_syntax_parser.cpp

 // Copyright 2016 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/src/fpdfapi/fpdf_parser/cpdf_syntax_parser.h"
 
 #include <vector>
 
 #include "core/include/fpdfapi/fpdf_module.h"
 #include "core/include/fpdfapi/fpdf_parser.h"
+#include "core/include/fpdfapi/ipdf_crypto_handler.h"
 #include "core/include/fxcrt/fx_ext.h"
 #include "core/src/fpdfapi/fpdf_parser/fpdf_parser_utility.h"
 #include "third_party/base/numerics/safe_math.h"
 
 namespace {
 
 struct SearchTagRecord {
   const char* m_pTag;
   FX_DWORD m_Len;
   FX_DWORD m_Offset;
@@ skipping 606 matching lines @@
   if (pLenObj && differingObjNum)
     len = pLenObj->GetInteger();
 
   // Locate the start of stream.
   ToNextLine();
   FX_FILESIZE streamStartPos = m_Pos;
 
   const CFX_ByteStringC kEndStreamStr("endstream");
   const CFX_ByteStringC kEndObjStr("endobj");
 
-  CPDF_CryptoHandler* pCryptoHandler =
+  IPDF_CryptoHandler* pCryptoHandler =
       objnum == (FX_DWORD)m_MetadataObjnum ? nullptr : m_pCryptoHandler.get();
   if (!pCryptoHandler) {
     FX_BOOL bSearchForKeyword = TRUE;
     if (len >= 0) {
       pdfium::base::CheckedNumeric<FX_FILESIZE> pos = m_Pos;
       pos += len;
       if (pos.IsValid() && pos.ValueOrDie() < m_FileLen)
         m_Pos = pos.ValueOrDie();
 
       m_Pos += ReadEOLMarkers(m_Pos);
@@ skipping 317 matching lines @@
       match = ch == tag[0] ? 1 : 0;
     }
 
     if (limit && m_Pos == limit)
       return -1;
   }
   return -1;
 }
 
 void CPDF_SyntaxParser::SetEncrypt(
-    std::unique_ptr<CPDF_CryptoHandler> pCryptoHandler) {
+    std::unique_ptr<IPDF_CryptoHandler> pCryptoHandler) {
   m_pCryptoHandler = std::move(pCryptoHandler);
 }