Roll src/third_party/libvpx/source/libvpx/ 91f87e751..4d4231352 (50 commits).

third_party/libvpx/source/config/linux/ia32/vpx_dsp_rtcd.h

Index: third_party/libvpx/source/config/linux/ia32/vpx_dsp_rtcd.h
diff --git a/third_party/libvpx/source/config/linux/ia32/vpx_dsp_rtcd.h b/third_party/libvpx/source/config/linux/ia32/vpx_dsp_rtcd.h
index 727a39ed3f84476c97196ba82022ca6cd314851b..20ab4d271042558962b3d595bacb3a7df0849775 100644
--- a/third_party/libvpx/source/config/linux/ia32/vpx_dsp_rtcd.h
+++ b/third_party/libvpx/source/config/linux/ia32/vpx_dsp_rtcd.h
@@ -1095,6 +1095,10 @@ void vpx_highbd_idct16x16_256_add_c(const tran_low_t *input, uint8_t *dest, int
 void vpx_highbd_idct16x16_256_add_sse2(const tran_low_t *input, uint8_t *dest, int stride, int bd);
 RTCD_EXTERN void (*vpx_highbd_idct16x16_256_add)(const tran_low_t *input, uint8_t *dest, int stride, int bd);
 
+void vpx_highbd_idct16x16_38_add_c(const tran_low_t *input, uint8_t *dest, int stride, int bd);
+void vpx_highbd_idct16x16_256_add_sse2(const tran_low_t *input, uint8_t *dest, int stride, int bd);
+RTCD_EXTERN void (*vpx_highbd_idct16x16_38_add)(const tran_low_t *input, uint8_t *dest, int stride, int bd);
+
 void vpx_highbd_idct32x32_1024_add_c(const tran_low_t *input, uint8_t *dest, int stride, int bd);
 #define vpx_highbd_idct32x32_1024_add vpx_highbd_idct32x32_1024_add_c
 
@@ -2443,6 +2447,8 @@ static void setup_rtcd_internal(void)
     if (flags & HAS_SSE2) vpx_highbd_idct16x16_10_add = vpx_highbd_idct16x16_10_add_sse2;
     vpx_highbd_idct16x16_256_add = vpx_highbd_idct16x16_256_add_c;
     if (flags & HAS_SSE2) vpx_highbd_idct16x16_256_add = vpx_highbd_idct16x16_256_add_sse2;
+    vpx_highbd_idct16x16_38_add = vpx_highbd_idct16x16_38_add_c;
+    if (flags & HAS_SSE2) vpx_highbd_idct16x16_38_add = vpx_highbd_idct16x16_256_add_sse2;
     vpx_highbd_idct32x32_1_add = vpx_highbd_idct32x32_1_add_c;
     if (flags & HAS_SSE2) vpx_highbd_idct32x32_1_add = vpx_highbd_idct32x32_1_add_sse2;
     vpx_highbd_idct4x4_16_add = vpx_highbd_idct4x4_16_add_c;