The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/859b0299534a83a7f6ad8c307fe9c4227c569b53

commit 859b0299534a83a7f6ad8c307fe9c4227c569b53
Author: Findit <findit-for-me@appspot.gserviceaccount.com>
Date: Fri Oct 19 00:09:20 2018

Revert "NetworkService: Report data use of URLLoader to browser process"

This reverts commit adb22130c129125461857eafe66342209939b71b.

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 600928 as the
culprit for flakes in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/flake/flake-culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyQwsSDEZsYWtlQ3VscHJpdCIxY2hyb21pdW0vYWRiMjIxMzBjMTI5MTI1NDYxODU3ZWFmZTY2MzQyMjA5OTM5YjcxYgw

Sample Failed Build: https://ci.chromium.org/buildbot/chromium.linux/linux-xenial-rel/4268

Sample Failed Step: network_service_browser_tests on Ubuntu-16.04

Sample Flaky Test: DataUseMeasurementBrowserTestWithDataSaverEnabled.CheckServicesDataUseRecorded

Original change's description:
> NetworkService: Report data use of URLLoader to browser process
> 
> When the requests complete, the total received and sent bytes are sent
> to browser process. ChromeDataUseMeasurement records metrics on Chrome-services
> data usage and updates metrics service.
> 
> Subsequent CLs will record more metrics and also report this to data
> reduction proxy settings page.
> 
> When NetworkService is disabled, DataUseMeasurement will get network
> delegate callbacks and record metrics.
> 
> Bug:  808498 
> Cq-Include-Trybots: luci.chromium.try:linux_mojo
> Change-Id: I113e480e4e1c67a65ff7461eb5ae2166a6b038d2
> Reviewed-on: https://chromium-review.googlesource.com/c/1274202
> Commit-Queue: rajendrant <rajendrant@chromium.org>
> Reviewed-by: Tarun Bansal <tbansal@chromium.org>
> Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
> Reviewed-by: John Abd-El-Malek <jam@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#600928}

Change-Id: I6fdfa077e01fb3ae0693be88eb58361a6bb17a13
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug:  808498 ,  896942 
Cq-Include-Trybots: luci.chromium.try:linux_mojo
Reviewed-on: https://chromium-review.googlesource.com/c/1290137
Cr-Commit-Position: refs/heads/master@{#600975}
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/chrome/browser/browser_process.h
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/chrome/browser/browser_process_impl.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/chrome/browser/browser_process_impl.h
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/chrome/browser/chrome_content_browser_client.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/chrome/browser/chrome_content_browser_client.h
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/chrome/browser/data_use_measurement/chrome_data_use_ascriber.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/chrome/browser/data_use_measurement/chrome_data_use_measurement.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/chrome/browser/data_use_measurement/chrome_data_use_measurement.h
[delete] https://crrev.com/ce5c2317dab655c8913ff31cbee0b438138f1b7f/chrome/browser/data_use_measurement/data_use_measurement_browsertest.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/chrome/test/BUILD.gn
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/chrome/test/base/testing_browser_process.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/chrome/test/base/testing_browser_process.h
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/components/data_use_measurement/core/BUILD.gn
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/components/data_use_measurement/core/DEPS
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/components/data_use_measurement/core/data_use_measurement.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/components/data_use_measurement/core/data_use_measurement.h
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/components/data_use_measurement/core/data_use_measurement_unittest.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/components/data_use_measurement/core/data_use_network_delegate.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/components/data_use_measurement/core/data_use_network_delegate_unittest.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/content/browser/network_service_client.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/content/browser/network_service_client.h
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/content/public/browser/content_browser_client.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/content/public/browser/content_browser_client.h
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/services/network/public/mojom/network_service.mojom
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/services/network/test/test_network_service_client.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/services/network/test/test_network_service_client.h
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/services/network/url_loader.cc
[modify] https://crrev.com/859b0299534a83a7f6ad8c307fe9c4227c569b53/services/network/url_loader_unittest.cc

The culprit CL is reverted.