libwebp: update snapshot to v0.3.0-rc6

third_party/libwebp/utils/quant_levels.h

 // Copyright 2011 Google Inc. All Rights Reserved.
 //
 // This code is licensed under the same terms as WebM:
 //  Software License Agreement:  http://www.webmproject.org/license/software/
 //  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
 // -----------------------------------------------------------------------------
 //
 // Alpha plane quantization utility
 //
 // Author:  Vikas Arora (vikasa@google.com)
 
 #ifndef WEBP_UTILS_QUANT_LEVELS_H_
 #define WEBP_UTILS_QUANT_LEVELS_H_
 
 #include <stdlib.h>
 
 #include "../webp/types.h"
 
 #if defined(__cplusplus) || defined(c_plusplus)
 extern "C" {
 #endif
 
 // Replace the input 'data' of size 'width'x'height' with 'num-levels'
 // quantized values. If not NULL, 'sse' will contain the sum of squared error.
 // Valid range for 'num_levels' is [2, 256].
 // Returns false in case of error (data is NULL, or parameters are invalid).
 int QuantizeLevels(uint8_t* const data, int width, int height, int num_levels,
                    uint64_t* const sse);
 
-// Apply post-processing to input 'data' of size 'width'x'height' assuming
-// that the source was quantized to a reduced number of levels.
-// Returns false in case of error (data is NULL, invalid parameters, ...).
-int DequantizeLevels(uint8_t* const data, int width, int height);
-
 #if defined(__cplusplus) || defined(c_plusplus)
 }    // extern "C"
 #endif
 
 #endif  /* WEBP_UTILS_QUANT_LEVELS_H_ */