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

core/src/fpdfdoc/doc_bookmark.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 <memory>
 #include <vector>
 
+#include "core/include/fpdfapi/cpdf_document.h"
 #include "core/include/fpdfdoc/fpdf_doc.h"
 
 CPDF_Bookmark CPDF_BookmarkTree::GetFirstChild(
     const CPDF_Bookmark& parent) const {
   if (!parent.GetDict()) {
     CPDF_Dictionary* pRoot = m_pDocument->GetRoot()->GetDictBy("Outlines");
     if (!pRoot)
       return CPDF_Bookmark();
     return CPDF_Bookmark(pRoot->GetDictBy("First"));
   }
@@ skipping 63 matching lines @@
   if (CPDF_Array* pArray = pDest->AsArray())
     return CPDF_Dest(pArray);
   return CPDF_Dest();
 }
 CPDF_Action CPDF_Bookmark::GetAction() const {
   if (!m_pDict) {
     return CPDF_Action();
   }
   return CPDF_Action(m_pDict->GetDictBy("A"));
 }