Update libwebp to 0.4.0

third_party/libwebp/utils/color_cache.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.
 // -----------------------------------------------------------------------------
 //
 // Color Cache for WebP Lossless
 //
 // Authors: Jyrki Alakuijala (jyrki@google.com)
 //          Urvang Joshi (urvang@google.com)
 
 #ifndef WEBP_UTILS_COLOR_CACHE_H_
 #define WEBP_UTILS_COLOR_CACHE_H_
 
 #include "../webp/types.h"
 
-#if defined(__cplusplus) || defined(c_plusplus)
+#ifdef __cplusplus
 extern "C" {
 #endif
 
 // Main color cache struct.
 typedef struct {
   uint32_t *colors_;  // color entries
   int hash_shift_;    // Hash shift: 32 - hash_bits.
 } VP8LColorCache;
 
 static const uint32_t kHashMul = 0x1e35a7bd;
@@ skipping 25 matching lines @@
 
 // Initializes the color cache with 'hash_bits' bits for the keys.
 // Returns false in case of memory error.
 int VP8LColorCacheInit(VP8LColorCache* const color_cache, int hash_bits);
 
 // Delete the memory associated to color cache.
 void VP8LColorCacheClear(VP8LColorCache* const color_cache);
 
 //------------------------------------------------------------------------------
 
-#if defined(__cplusplus) || defined(c_plusplus)
+#ifdef __cplusplus
 }
 #endif
 
 #endif  // WEBP_UTILS_COLOR_CACHE_H_