Cherry-pick 272448.9@safari-7618-branch (965fd49). https://bugs.webki…

…t.org/show_bug.cgi?id=266695

    Potential 'overflow' issue commited to upstream libwebrtc
    rdar://119595026

    Reviewed by Jean-Yves Avenard.

    Cherry-picking of webmproject/libvpx@193b151

    * Source/ThirdParty/libwebrtc/Source/third_party/libvpx/source/libvpx/test/encode_api_test.cc:
    * Source/ThirdParty/libwebrtc/Source/third_party/libvpx/source/libvpx/vp8/encoder/encodeframe.c:
    (encode_mb_row):

    Canonical link: https://commits.webkit.org/272448.9@safari-7618-branch

Canonical link: https://commits.webkit.org/266719.382@webkitglib/2.42

Source/ThirdParty/libwebrtc/Source/third_party/libvpx/source/libvpx/vp8/encoder/encodeframe.c

@@ -453,13 +453,21 @@ static void encode_mb_row(VP8_COMP *cpi, VP8_COMMON *cm, int mb_row,
     x->active_ptr = cpi->active_map + map_index + mb_col;
 
     if (cm->frame_type == KEY_FRAME) {
-      *totalrate += vp8cx_encode_intra_macroblock(cpi, x, tp);
+      const int intra_rate_cost = vp8cx_encode_intra_macroblock(cpi, x, tp);
+      if (INT_MAX - *totalrate > intra_rate_cost)
+        *totalrate += intra_rate_cost;
+      else
+        *totalrate = INT_MAX;
 #ifdef MODE_STATS
       y_modes[xd->mbmi.mode]++;
 #endif
     } else {
-      *totalrate += vp8cx_encode_inter_macroblock(
+      const int inter_rate_cost = vp8cx_encode_inter_macroblock(
           cpi, x, tp, recon_yoffset, recon_uvoffset, mb_row, mb_col);
+      if (INT_MAX - *totalrate > inter_rate_cost)
+        *totalrate += inter_rate_cost;
+      else
+        *totalrate = INT_MAX;
 
 #ifdef MODE_STATS
       inter_y_modes[xd->mbmi.mode]++;