Fixup incorrect include guards.

xfa/include/fxfa/fxfa.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 FXFA_H_
-#define FXFA_H_
+#ifndef XFA_INCLUDE_FXFA_FXFA_H_
+#define XFA_INCLUDE_FXFA_FXFA_H_
 
 #include <vector>
 
 class CFX_Graphics;
 class CPDF_Document;
 class CXFA_Node;
 class CXFA_NodeList;
 class CXFA_WidgetAcc;
 class IFDE_XMLElement;
 class IFWL_AdapterTimerMgr;
@@ skipping 817 matching lines @@
                                  FX_FILESIZE offset = 0,
                                  size_t size = 0) = 0;
   virtual void FinishChecksum() = 0;
   virtual void GetChecksum(CFX_ByteString& bsChecksum) = 0;
 
  protected:
   ~IXFA_ChecksumContext() {}
 };
 IXFA_ChecksumContext* XFA_Checksum_Create();
 
-#endif  // FXFA_H_
+#endif  // XFA_INCLUDE_FXFA_FXFA_H_