Update libwebp to 0.4.0

third_party/libwebp/enc/vp8li.h

 // Copyright 2012 Google Inc. All Rights Reserved.
 //
 // Use of this source code is governed by a BSD-style license
 // that can be found in the COPYING file in the root of the source
 // tree. An additional intellectual property rights grant can be found
 // in the file PATENTS. All contributing project authors may
 // be found in the AUTHORS file in the root of the source tree.
 // -----------------------------------------------------------------------------
 //
 // Lossless encoder: internal header.
 //
 // Author: Vikas Arora (vikaas.arora@gmail.com)
 
 #ifndef WEBP_ENC_VP8LI_H_
 #define WEBP_ENC_VP8LI_H_
 
 #include "./histogram.h"
 #include "../utils/bit_writer.h"
 #include "../webp/encode.h"
 #include "../webp/format_constants.h"
 
-#if defined(__cplusplus) || defined(c_plusplus)
+#ifdef __cplusplus
 extern "C" {
 #endif
 
 typedef struct {
   const WebPConfig* config_;    // user configuration and parameters
   const WebPPicture* pic_;      // input picture.
 
   uint32_t* argb_;              // Transformed argb image data.
   uint32_t* argb_scratch_;      // Scratch memory for argb rows
                                 // (used for prediction).
@@ skipping 23 matching lines @@
 int VP8LEncodeImage(const WebPConfig* const config,
                     const WebPPicture* const picture);
 
 // Encodes the main image stream using the supplied bit writer.
 WebPEncodingError VP8LEncodeStream(const WebPConfig* const config,
                                    const WebPPicture* const picture,
                                    VP8LBitWriter* const bw);
 
 //------------------------------------------------------------------------------
 
-#if defined(__cplusplus) || defined(c_plusplus)
+#ifdef __cplusplus
 }    // extern "C"
 #endif
 
 #endif  /* WEBP_ENC_VP8LI_H_ */