GitLab

- Fixed fetcher crash because ResourceRequest was null if a second
request was asked but it was build in ctor.
- Fixed a wrong usage of OneOffTaskInfo window.
- Added unit test to verify the start/end window and backoff delay
in task info.

- If debug switch instant fetch on, we always schedule a fetch task
on service startup once, don't do recurring fetching task.

Bug: 1083532
Change-Id: I8c1a29bc7c7692b6c59a2de958589b41ca7957c1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2207616
Commit-Queue: Hesen Zhang <hesen@chromium.org>
Auto-Submit: Hesen Zhang <hesen@chromium.org>
Reviewed-by: Xing Liu <xingliu@chromium.org>
Reviewed-by: Shakti Sahu <shaktisahu@chromium.org>
Reviewed-by: Min Qin <qinmin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#769910}