libvpx: Pull from upstream

source/libvpx/vp8/encoder/pickinter.c

Index: source/libvpx/vp8/encoder/pickinter.c
diff --git a/source/libvpx/vp8/encoder/pickinter.c b/source/libvpx/vp8/encoder/pickinter.c
index f3443dbccdc85e250fce599d1c335f072ba51e3d..c41005a3bacfb377b72aaf107082a4963108ec61 100644
--- a/source/libvpx/vp8/encoder/pickinter.c
+++ b/source/libvpx/vp8/encoder/pickinter.c
@@ -72,7 +72,7 @@ static int macroblock_corner_grad(unsigned char* signal, int stride,
   int y2 = signal[offsetx * stride + offsety + sgny];
   int y3 = signal[(offsetx + sgnx) * stride + offsety];
   int y4 = signal[(offsetx + sgnx) * stride + offsety + sgny];
-  return MAX(MAX(abs(y1 - y2), abs(y1 - y3)), abs(y1 - y4));
+  return VPXMAX(VPXMAX(abs(y1 - y2), abs(y1 - y3)), abs(y1 - y4));
 }
 
 static int check_dot_artifact_candidate(VP8_COMP *cpi,
@@ -1136,8 +1136,9 @@ void vp8_pick_inter_mode(VP8_COMP *cpi, MACROBLOCK *x, int recon_yoffset,
 #if CONFIG_MULTI_RES_ENCODING
             if (parent_ref_valid && (parent_ref_frame == this_ref_frame) &&
                 dissim <= 2 &&
-                MAX(abs(best_ref_mv.as_mv.row - parent_ref_mv.as_mv.row),
-                    abs(best_ref_mv.as_mv.col - parent_ref_mv.as_mv.col)) <= 4)
+                VPXMAX(abs(best_ref_mv.as_mv.row - parent_ref_mv.as_mv.row),
+                       abs(best_ref_mv.as_mv.col - parent_ref_mv.as_mv.col)) <=
+                    4)
             {
                 d->bmi.mv.as_int = mvp_full.as_int;
                 mode_mv[NEWMV].as_int = mvp_full.as_int;
@@ -1240,7 +1241,10 @@ void vp8_pick_inter_mode(VP8_COMP *cpi, MACROBLOCK *x, int recon_yoffset,
             }
 
             mode_mv[NEWMV].as_int = d->bmi.mv.as_int;
-
+            // The clamp below is not necessary from the perspective
+            // of VP8 bitstream, but is added to improve ChromeCast
+            // mirroring's robustness. Please do not remove.
+            vp8_clamp_mv2(&mode_mv[this_mode], xd);
             /* mv cost; */
             rate2 += vp8_mv_bit_cost(&mode_mv[NEWMV], &best_ref_mv,
                                      cpi->mb.mvcost, 128);
@@ -1248,7 +1252,6 @@ void vp8_pick_inter_mode(VP8_COMP *cpi, MACROBLOCK *x, int recon_yoffset,
 
         case NEARESTMV:
         case NEARMV:
-
             if (mode_mv[this_mode].as_int == 0)
                 continue;