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

core/src/fpdfdoc/doc_ap.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/fpdfdoc/fpdf_ap.h"
 #include "core/include/fpdfdoc/fpdf_doc.h"
 #include "core/include/fpdfdoc/fpdf_vt.h"
 #include "core/src/fpdfdoc/doc_utils.h"
 #include "core/src/fpdfdoc/pdf_vt.h"
 
 #define PBS_SOLID 0
 #define PBS_DASH 1
 #define PBS_BEVELED 2
 #define PBS_INSET 3
@@ skipping 907 matching lines @@
     case CPVT_Color::kCMYK:
       sColorStream << color.fColor1 << " " << color.fColor2 << " "
                    << color.fColor3 << " " << color.fColor4 << " "
                    << (bFillOrStroke ? "k" : "K") << "\n";
       break;
     case CPVT_Color::kTransparent:
       break;
   }
   return sColorStream.GetByteString();
 }