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

core/src/fpdfapi/fpdf_edit/fpdf_edit_image.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/cpdf_document.h"
 #include "core/include/fpdfapi/fpdf_module.h"
 #include "core/include/fpdfapi/fpdf_page.h"
 #include "core/include/fpdfapi/fpdf_render.h"
 #include "core/include/fxcodec/fx_codec.h"
 #include "core/src/fpdfapi/fpdf_page/pageint.h"
 #include "core/src/fpdfapi/fpdf_render/render_int.h"
 
 CPDF_Dictionary* CPDF_Image::InitJPEG(uint8_t* pData, FX_DWORD size) {
   int32_t width;
   int32_t height;
@@ skipping 360 matching lines @@
     m_pStream->InitStreamFromFile(pFileRead, pDict);
   }
   m_bIsMask = pBitmap->IsAlphaMask();
   m_Width = BitmapWidth;
   m_Height = BitmapHeight;
   FX_Free(dest_buf);
 }
 void CPDF_Image::ResetCache(CPDF_Page* pPage, const CFX_DIBitmap* pBitmap) {
   pPage->GetRenderCache()->ResetBitmap(m_pStream, pBitmap);
 }