Fix ALL the include guards.

core/include/fxcodec/fx_codec_provider.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_CODEC_PROVIDER_H_
-#define _FX_CODEC_PROVIDER_H_
+#ifndef CORE_INCLUDE_FXCODEC_FX_CODEC_PROVIDER_H_
+#define CORE_INCLUDE_FXCODEC_FX_CODEC_PROVIDER_H_
+
 class IFX_JpegProvider
 {
 public:
     virtual void                Release() = 0;
 
     virtual void*               CreateDecoder(FX_LPCBYTE src_buf, FX_DWORD src_size, int width, int height, int nComps, FX_BOOL ColorTransform) = 0;
 
 
     virtual void                DestroyDecoder(void* pDecoder) = 0;
 
@@ skipping 26 matching lines @@
 
 
     virtual FX_BOOL             ReadScanline(void* pContext, FX_LPBYTE dest_buf) = 0;
 
 
     virtual FX_DWORD    GetAvailInput(void* pContext, FX_LPBYTE* avail_buf_ptr = NULL) = 0;
 
 protected:
     ~IFX_JpegProvider() { }
 };
-#endif
+
+#endif  // CORE_INCLUDE_FXCODEC_FX_CODEC_PROVIDER_H_