scale1 == 31 if and only if w10 == 0. So even though 1 << scale1 overflows, we know that the result of the multiplication should be 0. Handle that case. BUG=chromium:615818 Review-Url: https://codereview.webrtc.org/2258543002 Cr-Commit-Position: refs/heads/master@{#13847}