Fix ALL the include guards.

core/include/fpdfapi/fpdf_objects.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 _FPDF_OBJECTS_
-#define _FPDF_OBJECTS_
-#ifndef _FXCRT_EXTENSION_
+#ifndef CORE_INCLUDE_FPDFAPI_FPDF_OBJECTS_H_
+#define CORE_INCLUDE_FPDFAPI_FPDF_OBJECTS_H_
+
 #include "../fxcrt/fx_ext.h"
-#endif
+
 class CPDF_Document;
 class CPDF_IndirectObjects;
 class CPDF_Null;
 class CPDF_Boolean;
 class CPDF_Number;
 class CPDF_String;
 class CPDF_Stream;
 class CPDF_StreamAcc;
 class CPDF_StreamFilter;
 class CPDF_Array;
@@ skipping 713 matching lines @@
         m_IndirectObjs.GetNextAssoc(rPos, (void*&)objnum, (void*&)pObject);
     }
 protected:
 
     CFX_MapPtrToPtr                     m_IndirectObjs;
 
     IPDF_DocParser*                     m_pParser;
 
     FX_DWORD                            m_LastObjNum;
 };
-#endif
+
+#endif  // CORE_INCLUDE_FPDFAPI_FPDF_OBJECTS_H_