Fixing clang-tidy warning.

Bug: v8:8015
Change-Id: I2ac8b12c040af2ad6122ce14eef8b4f8375e46ac
Reviewed-on: https://chromium-review.googlesource.com/1219708Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Florian Sattler <sattlerf@google.com>
Cr-Commit-Position: refs/heads/master@{#55814}