Update libwebp to 0.4.0

third_party/libwebp/enc/tree.c

Index: third_party/libwebp/enc/tree.c
diff --git a/third_party/libwebp/enc/tree.c b/third_party/libwebp/enc/tree.c
index ecd8fb910e3b4ecf802059df81814cf11d41dcfd..e5d05e5221eac2bd3e39753ed3bc68ff5d834636 100644
--- a/third_party/libwebp/enc/tree.c
+++ b/third_party/libwebp/enc/tree.c
@@ -7,23 +7,18 @@
 // be found in the AUTHORS file in the root of the source tree.
 // -----------------------------------------------------------------------------
 //
-// Token probabilities
+// Coding of token probabilities, intra modes and segments.
 //
 // Author: Skal (pascal.massimino@gmail.com)
 
 #include "./vp8enci.h"
 
-#if defined(__cplusplus) || defined(c_plusplus)
-extern "C" {
-#endif
-
 //------------------------------------------------------------------------------
 // Default probabilities
 
 // Paragraph 13.5
 const uint8_t
   VP8CoeffsProba0[NUM_TYPES][NUM_BANDS][NUM_CTX][NUM_PROBAS] = {
-  // genereated using vp8_default_coef_probs() in entropy.c:129
   { { { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
       { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
       { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 }
@@ -320,7 +315,7 @@ void VP8CodeIntraModes(VP8Encoder* const enc) {
   VP8EncIterator it;
   VP8IteratorInit(enc, &it);
   do {
-    const VP8MBInfo* mb = it.mb_;
+    const VP8MBInfo* const mb = it.mb_;
     const uint8_t* preds = it.preds_;
     if (enc->segment_hdr_.update_map_) {
       PutSegment(bw, mb->segment_, enc->proba_.segments_);
@@ -345,7 +340,7 @@ void VP8CodeIntraModes(VP8Encoder* const enc) {
       }
     }
     PutUVMode(bw, mb->uv_mode_);
-  } while (VP8IteratorNext(&it, 0));
+  } while (VP8IteratorNext(&it));
 }
 
 //------------------------------------------------------------------------------
@@ -507,6 +502,3 @@ void VP8WriteProbas(VP8BitWriter* const bw, const VP8Proba* const probas) {
   }
 }
 
-#if defined(__cplusplus) || defined(c_plusplus)
-}    // extern "C"
-#endif