libvpx: Pull from upstream

source/libvpx/vp9/encoder/vp9_block.h

Index: source/libvpx/vp9/encoder/vp9_block.h
diff --git a/source/libvpx/vp9/encoder/vp9_block.h b/source/libvpx/vp9/encoder/vp9_block.h
index 68174a6cc8845a56a76f43b90f0917c691b29a0e..04a1b8f3c2f041fb4815f2acf194bad5560de991 100644
--- a/source/libvpx/vp9/encoder/vp9_block.h
+++ b/source/libvpx/vp9/encoder/vp9_block.h
@@ -118,6 +118,10 @@ struct macroblock {
   // Used to store sub partition's choices.
   MV pred_mv[MAX_REF_FRAMES];
 
+  // Strong color activity detection. Used in RTC coding mode to enhance
+  // the visual quality at the boundary of moving color objects.
+  uint8_t color_sensitivity[2];
+
   void (*fwd_txm4x4)(const int16_t *input, tran_low_t *output, int stride);
   void (*itxm_add)(const tran_low_t *input, uint8_t *dest, int stride, int eob);
 #if CONFIG_VP9_HIGHBITDEPTH