Split CPDF_SyntaxParser into its own named .cpp/.h files.

core/src/fpdfapi/fpdf_parser/fpdf_parser_fdf.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/include/fpdfapi/fpdf_parser.h"
 
 #include "core/include/fpdfapi/fpdf_serial.h"
+#include "core/src/fpdfapi/fpdf_parser/cpdf_syntax_parser.h"
 
 CFDF_Document::CFDF_Document() : CPDF_IndirectObjectHolder(NULL) {
   m_pRootDict = NULL;
   m_pFile = NULL;
   m_bOwnFile = FALSE;
 }
 CFDF_Document::~CFDF_Document() {
   if (m_bOwnFile && m_pFile) {
     m_pFile->Release();
   }
@@ skipping 67 matching lines @@
     return FALSE;
   }
   buf << "%FDF-1.2\r\n";
   for (const auto& pair : m_IndirectObjs) {
     buf << pair.first << " 0 obj\r\n" << pair.second << "\r\nendobj\r\n\r\n";
   }
   buf << "trailer\r\n<</Root " << m_pRootDict->GetObjNum()
       << " 0 R>>\r\n%%EOF\r\n";
   return TRUE;
 }