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

fpdfsdk/src/fpdf_flatten.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 "public/fpdf_flatten.h"
 
 #include <algorithm>
 
+#include "core/include/fpdfapi/cpdf_document.h"
 #include "fpdfsdk/include/fsdk_define.h"
 
 typedef CFX_ArrayTemplate<CPDF_Dictionary*> CPDF_ObjectArray;
 typedef CFX_ArrayTemplate<CFX_FloatRect> CPDF_RectArray;
 
 enum FPDF_TYPE { MAX, MIN };
 enum FPDF_VALUE { TOP, LEFT, RIGHT, BOTTOM };
 
 FX_BOOL IsValiableRect(CFX_FloatRect rect, CFX_FloatRect rcPage) {
   if (rect.left - rect.right > 0.000001f || rect.bottom - rect.top > 0.000001f)
@@ skipping 485 matching lines @@
     pNewXObject->SetData((const uint8_t*)sStream, sStream.GetLength(), FALSE,
                          FALSE);
   }
   pPageDict->RemoveAt("Annots");
 
   ObjectArray.RemoveAll();
   RectArray.RemoveAll();
 
   return FLATTEN_SUCCESS;
 }