GitLab

Removes unused code in processing arguments of callback
functions and callback interfaces.

Change-Id: I5a98a011ef5c42c69b9f9016579a19942cbad01f
Reviewed-on: https://chromium-review.googlesource.com/1067569Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561437}