libwebp: update to 0.4.1

third_party/libwebp/enc/cost.h

Index: third_party/libwebp/enc/cost.h
diff --git a/third_party/libwebp/enc/cost.h b/third_party/libwebp/enc/cost.h
index 3cbad1ae4c8adf315311116a107d541b7fdab678..5d107569b012c1d5ca9d4f95a615513aa2ca6ea6 100644
--- a/third_party/libwebp/enc/cost.h
+++ b/third_party/libwebp/enc/cost.h
@@ -14,12 +14,38 @@
 #ifndef WEBP_ENC_COST_H_
 #define WEBP_ENC_COST_H_
 
+#include <assert.h>
+#include <stdlib.h>
 #include "./vp8enci.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+// On-the-fly info about the current set of residuals. Handy to avoid
+// passing zillions of params.
+typedef struct {
+  int first;
+  int last;
+  const int16_t* coeffs;
+
+  int coeff_type;
+  ProbaArray* prob;
+  StatsArray* stats;
+  CostArray*  cost;
+} VP8Residual;
+
+void VP8InitResidual(int first, int coeff_type,
+                     VP8Encoder* const enc, VP8Residual* const res);
+
+typedef void (*VP8SetResidualCoeffsFunc)(const int16_t* const coeffs,
+                                         VP8Residual* const res);
+extern VP8SetResidualCoeffsFunc VP8SetResidualCoeffs;
+
+extern void VP8SetResidualCoeffsInit(void);  // must be called first
+
+int VP8RecordCoeffs(int ctx, const VP8Residual* const res);
+
 // approximate cost per level:
 extern const uint16_t VP8LevelFixedCosts[MAX_LEVEL + 1];
 extern const uint16_t VP8EntropyCost[256];        // 8bit fixed-point log(p)
@@ -29,6 +55,12 @@ static WEBP_INLINE int VP8BitCost(int bit, uint8_t proba) {
   return !bit ? VP8EntropyCost[proba] : VP8EntropyCost[255 - proba];
 }
 
+// Cost calculation function.
+typedef int (*VP8GetResidualCostFunc)(int ctx0, const VP8Residual* const res);
+extern VP8GetResidualCostFunc VP8GetResidualCost;
+
+extern void VP8GetResidualCostInit(void);  // must be called first
+
 // Level cost calculations
 extern const uint16_t VP8LevelCodes[MAX_VARIABLE_LEVEL][2];
 void VP8CalculateLevelCosts(VP8Proba* const proba);