Update libwebp to 0.4.0

third_party/libwebp/enc/syntax.c

 // Copyright 2011 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.
 // -----------------------------------------------------------------------------
 //
 // Header syntax writing
 //
 // Author: Skal (pascal.massimino@gmail.com)
 
 #include <assert.h>
 
 #include "../utils/utils.h"
 #include "../webp/format_constants.h"  // RIFF constants
 #include "../webp/mux_types.h"         // ALPHA_FLAG
 #include "./vp8enci.h"
 
-#if defined(__cplusplus) || defined(c_plusplus)
-extern "C" {
-#endif
-
 //------------------------------------------------------------------------------
 // Helper functions
 
 static int IsVP8XNeeded(const VP8Encoder* const enc) {
   return !!enc->has_alpha_;  // Currently the only case when VP8X is needed.
                              // This could change in the future.
 }
 
 static int PutPaddingByte(const WebPPicture* const pic) {
   const uint8_t pad_byte[1] = { 0 };
@@ skipping 383 matching lines @@
     ok = PutPaddingByte(pic);
   }
 
   enc->coded_size_ = (int)(CHUNK_HEADER_SIZE + riff_size);
   ok = ok && WebPReportProgress(pic, final_percent, &enc->percent_);
   return ok;
 }
 
 //------------------------------------------------------------------------------
 
-#if defined(__cplusplus) || defined(c_plusplus)
-}    // extern "C"
-#endif