Update libwebp to 0.4.0

third_party/libwebp/webp/decode.h

Index: third_party/libwebp/webp/decode.h
diff --git a/third_party/libwebp/webp/decode.h b/third_party/libwebp/webp/decode.h
index 141f8618f5a1410b9b682b26a7c2779add4ced7b..0c3b62e215b8d726d55a35a27adfb564b15a4e64 100644
--- a/third_party/libwebp/webp/decode.h
+++ b/third_party/libwebp/webp/decode.h
@@ -16,11 +16,11 @@
 
 #include "./types.h"
 
-#if defined(__cplusplus) || defined(c_plusplus)
+#ifdef __cplusplus
 extern "C" {
 #endif
 
-#define WEBP_DECODER_ABI_VERSION 0x0201    // MAJOR(8b) + MINOR(8b)
+#define WEBP_DECODER_ABI_VERSION 0x0203    // MAJOR(8b) + MINOR(8b)
 
 // Note: forward declaring enumerations is not allowed in (strict) C and C++,
 // the types are left here for reference.
@@ -404,9 +404,9 @@ struct WebPBitstreamFeatures {
   int height;         // Height in pixels, as read from the bitstream.
   int has_alpha;      // True if the bitstream contains an alpha channel.
   int has_animation;  // True if the bitstream is an animation.
+  int format;         // 0 = undefined (/mixed), 1 = lossy, 2 = lossless
 
   // Unused for now:
-  int bitstream_version;        // should be 0 for now. TODO(later)
   int no_incremental_decoding;  // if true, using incremental decoding is not
                                 // recommended.
   int rotate;                   // TODO(later)
@@ -441,11 +441,12 @@ struct WebPDecoderOptions {
   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)
 
   // Unused for now:
   int force_rotation;                 // forced rotation (to be applied _last_)
   int no_enhancement;                 // if true, discard enhancement layer
-  uint32_t pad[6];                    // padding for later use
+  uint32_t pad[5];                    // padding for later use
 };
 
 // Main object storing the configuration for advanced decoding.
@@ -483,7 +484,7 @@ WEBP_EXTERN(WebPIDecoder*) WebPIDecode(const uint8_t* data, size_t data_size,
 WEBP_EXTERN(VP8StatusCode) WebPDecode(const uint8_t* data, size_t data_size,
                                       WebPDecoderConfig* config);
 
-#if defined(__cplusplus) || defined(c_plusplus)
+#ifdef __cplusplus
 }    // extern "C"
 #endif