Remove redundant argument, add a DCHECK and explicitly specify the
capture list of the lambdas.

R=ahaas@chromium.org

Bug: v8:7570
Change-Id: I09fc6004ffc5cdc7b4c153748ed95e86ae85aaa2
Reviewed-on: https://chromium-review.googlesource.com/998098Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52430}