libwebp: update to 0.4.2-rc2

third_party/libwebp/webp/decode.h

 // Copyright 2010 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.
 // -----------------------------------------------------------------------------
 //
 //  Main decoding functions for WebP images.
@@ skipping 426 matching lines @@
   int use_cropping;                   // if true, cropping is applied _first_
   int crop_left, crop_top;            // top-left position for cropping.
                                       // Will be snapped to even values.
   int crop_width, crop_height;        // dimension of the cropping area
   int use_scaling;                    // if true, scaling is applied _afterward_
   int scaled_width, scaled_height;    // final resolution
   int use_threads;                    // if true, use multi-threaded decoding
   int dithering_strength;             // dithering strength (0=Off, 100=full)
 #if WEBP_DECODER_ABI_VERSION > 0x0203
   int flip;                           // flip output vertically
+#endif
+#if WEBP_DECODER_ABI_VERSION > 0x0204
   int alpha_dithering_strength;       // alpha dithering strength in [0..100]
 #endif
 
   // Unused for now:
   int force_rotation;                 // forced rotation (to be applied _last_)
   int no_enhancement;                 // if true, discard enhancement layer
-#if WEBP_DECODER_ABI_VERSION > 0x0203
+#if WEBP_DECODER_ABI_VERSION < 0x0203
+  uint32_t pad[5];                    // padding for later use
+#elif WEBP_DECODER_ABI_VERSION < 0x0204
+  uint32_t pad[4];                    // padding for later use
+#else
   uint32_t pad[3];                    // padding for later use
-#else
-  uint32_t pad[5];                    // padding for later use
 #endif
 };
 
 // Main object storing the configuration for advanced decoding.
 struct WebPDecoderConfig {
   WebPBitstreamFeatures input;  // Immutable bitstream features (optional)
   WebPDecBuffer output;         // Output buffer (can point to external mem)
   WebPDecoderOptions options;   // Decoding options
 };
 
@@ skipping 23 matching lines @@
 // 'config' into account. Returns decoding status (which should be VP8_STATUS_OK
 // if the decoding was successful).
 WEBP_EXTERN(VP8StatusCode) WebPDecode(const uint8_t* data, size_t data_size,
                                       WebPDecoderConfig* config);
 
 #ifdef __cplusplus
 }    // extern "C"
 #endif
 
 #endif  /* WEBP_WEBP_DECODE_H_ */