Merge to XFA: Fix ALL the include guards.

core/include/fxcrt/fx_string.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 _FX_STRING_H_
-#define _FX_STRING_H_
+#ifndef CORE_INCLUDE_FXCRT_FX_STRING_H_
+#define CORE_INCLUDE_FXCRT_FX_STRING_H_
 
 #include <stdint.h>  // For intptr_t.
 #include <algorithm>
 
 #include "fx_memory.h"
 #include "fx_system.h"
 
 class CFX_BinaryBuf;
 class CFX_ByteString;
 class CFX_WideString;
@@ skipping 876 matching lines @@
 FX_STRSIZE FX_ftoa(FX_FLOAT f, FX_LPSTR buf);
 CFX_ByteString  FX_UTF8Encode(FX_LPCWSTR pwsStr, FX_STRSIZE len);
 inline CFX_ByteString   FX_UTF8Encode(FX_WSTR wsStr)
 {
     return FX_UTF8Encode(wsStr.GetPtr(), wsStr.GetLength());
 }
 inline CFX_ByteString   FX_UTF8Encode(const CFX_WideString &wsStr)
 {
     return FX_UTF8Encode(wsStr.c_str(), wsStr.GetLength());
 }
-#endif
+
+#endif  // CORE_INCLUDE_FXCRT_FX_STRING_H_