Fix all relative includes to third_party.

core/include/fpdfdoc/fpdf_doc.h

 // 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
 
 #ifndef CORE_INCLUDE_FPDFDOC_FPDF_DOC_H_
 #define CORE_INCLUDE_FPDFDOC_FPDF_DOC_H_
 
 #include <map>
 #include <vector>
 
-#include "../../../third_party/base/nonstd_unique_ptr.h"
 #include "../fpdfapi/fpdf_parser.h"
 #include "../fpdfapi/fpdf_render.h"
+#include "third_party/base/nonstd_unique_ptr.h"
 
 class CFieldTree;
 class CPDF_AAction;
 class CPDF_Action;
 class CPDF_ActionFields;
 class CPDF_Annot;
 class CPDF_AnnotList;
 class CPDF_ApSettings;
 class CPDF_Bookmark;
 class CPDF_BookmarkTree;
@@ skipping 1139 matching lines @@
                         FX_FLOAT fc[4],
                         const CFX_ByteStringC& csEntry);
 
   CFX_WideString GetCaption(const CFX_ByteStringC& csEntry);
 
   CPDF_Stream* GetIcon(const CFX_ByteStringC& csEntry);
   friend class CPDF_FormControl;
 };
 
 #endif  // CORE_INCLUDE_FPDFDOC_FPDF_DOC_H_