This patch fixes build error for 64bit platforms introduces in
https://codereview.chromium.org/2793323002
Error message from MIPS64 buildbot: error: implicit conversion loses
integer precision: 'long' to 'int' [-Werror,-Wshorten-64-to-32]

BUG=

Review-Url: https://codereview.chromium.org/2801713004
Cr-Commit-Position: refs/heads/master@{#44460}