Also remove an unnecessary AllowHandleDereference scope.

Bug: chromium:863155, v8:7790
Change-Id: I37a6efb0595d09ccf0a1e653620060a16fc96247
Reviewed-on: https://chromium-review.googlesource.com/1136444
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54440}