GitLab

Add a method in DownloadItem to get DownloadSchedule, this is needed
to plumb the data to download level db.

Bug: 1078454
Change-Id: Ifce1245a45a393d131901cb15257f74337146afb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2234131Reviewed-by: David Trainor <dtrainor@chromium.org>
Commit-Queue: Xing Liu <xingliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#776630}