The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c03ee35183d4b18e271e8c626b3c3597170e4faa

commit c03ee35183d4b18e271e8c626b3c3597170e4faa
Author: Mugdha Lakhani <nator@chromium.org>
Date: Wed May 23 15:30:43 2018

[Background Fetch] Cap downloads to downloadTotal.

downloadTotal can be set from BackgroundFetchOptions in the fetch()
call. After this change, if downloadTotal is set to a positive value,
we will start capping downloads to this value. This is to provide a
better user experience, given we surface downloadTotal as total
size of downloads in the UI.

Once as many bytes as downloadTotal are downloaded, and there are more
bytes to download, we cancel all active downloads and dispatch a
BackgroundFetchFail event.

There is no change in behavior if downloadTotal is set too high. It's in
the developers' interest to specify a correct downloadTotal, whenever
possible, to provide a good UI experience for the user. If set too high,
an inaccurate downloadTotal can cause the user to cancel fetch, for fear
of eating into data and storage resources.

Bug:  839438 
Change-Id: I710dfbb6ba0fd13de83f31f6b49a2ade46bae1da
Reviewed-on: https://chromium-review.googlesource.com/1067347
Reviewed-by: Peter Beverloo <peter@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Mugdha Lakhani <nator@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561095}
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/chrome/browser/background_fetch/background_fetch_browsertest.cc
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/chrome/browser/background_fetch/background_fetch_delegate_impl.cc
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/chrome/browser/background_fetch/background_fetch_delegate_impl.h
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/chrome/test/data/background_fetch/background_fetch.js
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/content/browser/background_fetch/background_fetch_context.cc
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/content/browser/background_fetch/background_fetch_context.h
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/content/browser/background_fetch/background_fetch_delegate_proxy.cc
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/content/browser/background_fetch/background_fetch_delegate_proxy.h
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/content/browser/background_fetch/background_fetch_delegate_proxy_unittest.cc
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/content/browser/background_fetch/background_fetch_job_controller.cc
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/content/browser/background_fetch/background_fetch_job_controller.h
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/content/browser/background_fetch/background_fetch_job_controller_unittest.cc
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/content/browser/background_fetch/background_fetch_scheduler.cc
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/content/browser/background_fetch/background_fetch_scheduler.h
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/content/browser/background_fetch/background_fetch_scheduler_unittest.cc
[modify] https://crrev.com/c03ee35183d4b18e271e8c626b3c3597170e4faa/content/public/browser/background_fetch_delegate.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f7451e312c9e7d9b845da7adf0f1998de99b10eb

commit f7451e312c9e7d9b845da7adf0f1998de99b10eb
Author: Tim Schumann <tschumann@chromium.org>
Date: Mon Jun 11 14:27:02 2018

Disable flaky BackgroundFetchBrowserTest tests.

-- BackgroundFetchBrowserTest.OfflineItemCollection_VerifyResourceDownloadedWhenDownloadTotalSmallerThanActualSize
-- BackgroundFetchBrowserTest.OfflineItemCollection_VerifyResourceDownloadedWhenDownloadTotalLargerThanActualSize

are flaky.
https://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=BackgroundFetchBrowserTest.OfflineItemCollection_VerifyResourceDownloadedWhenDownloadTotal.*ThanActualSize

TBR=peter@chromium.org

Bug:  851229 , 839438 
Change-Id: I0aee9f1fdbabcbe7802d85e3ee782b522a03ff61
Reviewed-on: https://chromium-review.googlesource.com/1095183
Commit-Queue: Tim Schumann <tschumann@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Reviewed-by: Tim Schumann <tschumann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565993}
[modify] https://crrev.com/f7451e312c9e7d9b845da7adf0f1998de99b10eb/chrome/browser/background_fetch/background_fetch_browsertest.cc

Resolving this bug since the flaky tests caused by the move to persistent downloads have been fixed.