Update libwebp to 0.4.0

third_party/libwebp/utils/filters.h

Index: third_party/libwebp/utils/filters.h
diff --git a/third_party/libwebp/utils/filters.h b/third_party/libwebp/utils/filters.h
index 1f5fa164f366739938b3b87231437482042f9abe..dde39cb5c406d39a68260f95326213fcb26ee683 100644
--- a/third_party/libwebp/utils/filters.h
+++ b/third_party/libwebp/utils/filters.h
@@ -16,7 +16,7 @@
 
 #include "../webp/types.h"
 
-#if defined(__cplusplus) || defined(c_plusplus)
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -34,7 +34,7 @@ typedef enum {
 typedef void (*WebPFilterFunc)(const uint8_t* in, int width, int height,
                                int stride, uint8_t* out);
 typedef void (*WebPUnfilterFunc)(int width, int height, int stride,
-                                 uint8_t* data);
+                                 int row, int num_rows, uint8_t* data);
 
 // Filter the given data using the given predictor.
 // 'in' corresponds to a 2-dimensional pixel array of size (stride * height)
@@ -44,13 +44,15 @@ typedef void (*WebPUnfilterFunc)(int width, int height, int stride,
 extern const WebPFilterFunc WebPFilters[WEBP_FILTER_LAST];
 
 // In-place reconstruct the original data from the given filtered data.
+// The reconstruction will be done for 'num_rows' rows starting from 'row'
+// (assuming rows upto 'row - 1' are already reconstructed).
 extern const WebPUnfilterFunc WebPUnfilters[WEBP_FILTER_LAST];
 
 // Fast estimate of a potentially good filter.
-extern WEBP_FILTER_TYPE EstimateBestFilter(const uint8_t* data,
-                                           int width, int height, int stride);
+WEBP_FILTER_TYPE EstimateBestFilter(const uint8_t* data,
+                                    int width, int height, int stride);
 
-#if defined(__cplusplus) || defined(c_plusplus)
+#ifdef __cplusplus
 }    // extern "C"
 #endif