libwebp: update snapshot to v0.3.0-rc6

third_party/libwebp/dsp/yuv.c

Index: third_party/libwebp/dsp/yuv.c
diff --git a/third_party/libwebp/dsp/yuv.c b/third_party/libwebp/dsp/yuv.c
index 7f05f9a3aa440ea658cc0f6dac80ffffc488e7d4..f8988bae118a3776b445966f4756bcc604893f12 100644
--- a/third_party/libwebp/dsp/yuv.c
+++ b/third_party/libwebp/dsp/yuv.c
@@ -15,7 +15,7 @@
 extern "C" {
 #endif
 
-enum { YUV_HALF = 1 << (YUV_FIX - 1) };
+#ifdef WEBP_YUV_USE_TABLE
 
 int16_t VP8kVToR[256], VP8kUToB[256];
 int32_t VP8kVToG[256], VP8kUToG[256];
@@ -33,6 +33,7 @@ void VP8YUVInit(void) {
   if (done) {
     return;
   }
+#ifndef USE_YUVj
   for (i = 0; i < 256; ++i) {
     VP8kVToR[i] = (89858 * (i - 128) + YUV_HALF) >> YUV_FIX;
     VP8kUToG[i] = -22014 * (i - 128) + YUV_HALF;
@@ -44,9 +45,29 @@ void VP8YUVInit(void) {
     VP8kClip[i - YUV_RANGE_MIN] = clip(k, 255);
     VP8kClip4Bits[i - YUV_RANGE_MIN] = clip((k + 8) >> 4, 15);
   }
+#else
+  for (i = 0; i < 256; ++i) {
+    VP8kVToR[i] = (91881 * (i - 128) + YUV_HALF) >> YUV_FIX;
+    VP8kUToG[i] = -22554 * (i - 128) + YUV_HALF;
+    VP8kVToG[i] = -46802 * (i - 128);
+    VP8kUToB[i] = (116130 * (i - 128) + YUV_HALF) >> YUV_FIX;
+  }
+  for (i = YUV_RANGE_MIN; i < YUV_RANGE_MAX; ++i) {
+    const int k = i;
+    VP8kClip[i - YUV_RANGE_MIN] = clip(k, 255);
+    VP8kClip4Bits[i - YUV_RANGE_MIN] = clip((k + 8) >> 4, 15);
+  }
+#endif
+
   done = 1;
 }
 
+#else
+
+void VP8YUVInit(void) {}
+
+#endif  // WEBP_YUV_USE_TABLE
+
 #if defined(__cplusplus) || defined(c_plusplus)
 }    // extern "C"
 #endif