Fixing clang-tidy warning.

Bug: v8:8015
Change-Id: I56b730814539df7fdc2e1e5fb06c8b2b104b5fc8
Reviewed-on: https://chromium-review.googlesource.com/1223830
Commit-Queue: Florian Sattler <sattlerf@google.com>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55915}