The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cfa1faaf7ad5b90f1acd674177edf5f67ce9f1a7

commit cfa1faaf7ad5b90f1acd674177edf5f67ce9f1a7
Author: Min Qin <qinmin@chromium.org>
Date: Fri May 18 21:02:18 2018

Fix an issue that DownloadRequestLimiter is bypassed for some downloads

When network service is enabled, only navigation triggered download uses
DownloadRequestLimiter.
However, for anchor elements with download attrbutes,
DownloadRequestLimiter is not used.
Since these download come with a valid WebContents, the behavior is wrong.
For comparison, DownloadRequestLimiter is applied when network service
is disabled for these downloads.

Bug:  843631 
Change-Id: Icf90ffdc8495f15d5a4cb3a5c56966dca2a95d4b
Reviewed-on: https://chromium-review.googlesource.com/1063021
Commit-Queue: Min Qin <qinmin@chromium.org>
Reviewed-by: Xing Liu <xingliu@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Cr-Commit-Position: refs/heads/master@{#560033}
[modify] https://crrev.com/cfa1faaf7ad5b90f1acd674177edf5f67ce9f1a7/chrome/browser/download/download_browsertest.cc
[modify] https://crrev.com/cfa1faaf7ad5b90f1acd674177edf5f67ce9f1a7/chrome/browser/download/download_request_limiter.cc
[modify] https://crrev.com/cfa1faaf7ad5b90f1acd674177edf5f67ce9f1a7/chrome/browser/download/download_request_limiter.h
[modify] https://crrev.com/cfa1faaf7ad5b90f1acd674177edf5f67ce9f1a7/chrome/browser/download/download_resource_throttle.cc
[add] https://crrev.com/cfa1faaf7ad5b90f1acd674177edf5f67ce9f1a7/chrome/test/data/download-anchor-script.html
[modify] https://crrev.com/cfa1faaf7ad5b90f1acd674177edf5f67ce9f1a7/content/browser/download/download_manager_impl.cc
[modify] https://crrev.com/cfa1faaf7ad5b90f1acd674177edf5f67ce9f1a7/content/browser/download/download_manager_impl.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2ea74ee49ab138b4192bfddd7726d97f20f0042b

commit 2ea74ee49ab138b4192bfddd7726d97f20f0042b
Author: John Abd-El-Malek <jam@chromium.org>
Date: Tue Jun 12 04:22:09 2018

Remove WebViewTest.DownloadPermission from network service test filter.

This was fixed in r560033.

Bug:  843631 
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_mojo
Change-Id: I01a3eb02695256f3d96c7e44cf099c237ff99997
Reviewed-on: https://chromium-review.googlesource.com/1096495
Reviewed-by: Min Qin <qinmin@chromium.org>
Commit-Queue: John Abd-El-Malek <jam@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566305}
[modify] https://crrev.com/2ea74ee49ab138b4192bfddd7726d97f20f0042b/testing/buildbot/filters/mojo.fyi.network_browser_tests.filter