The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1c96d7099d18403cf57602b7ab89bc379ebf5b74

commit 1c96d7099d18403cf57602b7ab89bc379ebf5b74
Author: Rayan Kanso <rayankans@chromium.org>
Date: Wed Jun 06 14:56:42 2018

[Background Fetch] Store failed fetches in Cache Storage.

Store failed fetches in the cache, since the download manager returns
useful information, such as the status code (404, 501, etc).

Bug: 848280
Change-Id: Ic2a229473756f6357d67d90bedf6e2d3e23bb7b4
Reviewed-on: https://chromium-review.googlesource.com/1086988
Reviewed-by: Peter Beverloo <peter@chromium.org>
Commit-Queue: Rayan Kanso <rayankans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#564891}
[modify] https://crrev.com/1c96d7099d18403cf57602b7ab89bc379ebf5b74/content/browser/background_fetch/storage/get_settled_fetches_task.cc
[modify] https://crrev.com/1c96d7099d18403cf57602b7ab89bc379ebf5b74/content/browser/background_fetch/storage/get_settled_fetches_task.h
[modify] https://crrev.com/1c96d7099d18403cf57602b7ab89bc379ebf5b74/content/browser/background_fetch/storage/mark_request_complete_task.cc
[modify] https://crrev.com/1c96d7099d18403cf57602b7ab89bc379ebf5b74/content/browser/background_fetch/storage/mark_request_complete_task.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7e41c74f2180d1ff7be85a908d47856cf939d402

commit 7e41c74f2180d1ff7be85a908d47856cf939d402
Author: Rayan Kanso <rayankans@chromium.org>
Date: Wed Jun 06 15:45:14 2018

[Background Fetch] Delete caches when registration is deleted.

Cleanup more thoroughly when a registration is deleted.
- All associated information in the ServiceWorker database
- The cache created to store responses.

Bug: 848280
Change-Id: I394651edb5be07cf7d2352ab10b5e232a027e158
Reviewed-on: https://chromium-review.googlesource.com/1088705
Commit-Queue: Rayan Kanso <rayankans@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#564904}
[modify] https://crrev.com/7e41c74f2180d1ff7be85a908d47856cf939d402/content/browser/background_fetch/background_fetch_data_manager.cc
[modify] https://crrev.com/7e41c74f2180d1ff7be85a908d47856cf939d402/content/browser/background_fetch/background_fetch_data_manager_unittest.cc
[modify] https://crrev.com/7e41c74f2180d1ff7be85a908d47856cf939d402/content/browser/background_fetch/storage/cleanup_task.cc
[modify] https://crrev.com/7e41c74f2180d1ff7be85a908d47856cf939d402/content/browser/background_fetch/storage/cleanup_task.h
[modify] https://crrev.com/7e41c74f2180d1ff7be85a908d47856cf939d402/content/browser/background_fetch/storage/delete_registration_task.cc
[modify] https://crrev.com/7e41c74f2180d1ff7be85a908d47856cf939d402/content/browser/background_fetch/storage/delete_registration_task.h