Fix ALL the include guards.

core/include/reflow/reflowengine.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 _REFLOW_ENGINE_H
-#define _REFLOW_ENGINE_H
+#ifndef CORE_INCLUDE_REFLOW_REFLOWENGINE_H_
+#define CORE_INCLUDE_REFLOW_REFLOWENGINE_H_
+
+#include "../fpdfapi/fpdf_pageobj.h"
 #include "../fpdfapi/fpdf_render.h"
+#include "../fpdfdoc/fpdf_tagged.h"
 #include "../fpdftext/fpdf_text.h"
 #include "fpdf_layout.h"
-#include "../fpdfapi/fpdf_pageobj.h"
-#include "../fpdfdoc/fpdf_tagged.h"
+
 class IPDF_ReflowedPage
 {
 public:
     static IPDF_ReflowedPage* Create();
 
     virtual ~IPDF_ReflowedPage() {}
     virtual CFX_PrivateData*    GetPrivateDataCtrl() = 0;
 
 
     virtual void                GetDisplayMatrix(CFX_AffineMatrix& matrix, FX_INT32 xPos, FX_INT32 yPos, FX_INT32 xSize, FX_INT32 ySize, FX_INT32 iRotate, const CFX_AffineMatrix* pPageMatrix) = 0;
@@ skipping 42 matching lines @@
     virtual void                Start(IPDF_ReflowedPage* pReflowPage, CFX_RenderDevice* pDevice, const CFX_AffineMatrix* pMatrix, IFX_Pause* pPause, int DitherBits ) = 0;
     virtual void                Continue(IFX_Pause* pPause) = 0;
     virtual int                 GetPosition() = 0;
 
 
     virtual void                                Clear() = 0;
 };
 IPDF_ReflowedPage* Create_ReflowPage();
 IPDF_ProgressiveReflowPageParser* Create_ReflowPageParser();
 IPDF_ProgressiveReflowPageRender* Create_ReflowPageRender();
-#endif
+
+#endif  // CORE_INCLUDE_REFLOW_REFLOWENGINE_H_