GitLab

Return of GetAllFileList is not used anywhere so it's safe to convert to
CancelCallbackOnce.

Bug: 1007686
Change-Id: I57ff303b8d34fab9926199615a95eb0e81937e31
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2304952Reviewed-by: Yoshiki Iguchi <yoshiki@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>
Cr-Commit-Position: refs/heads/master@{#790649}