The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/dce5056197537fe6cb55976cc7995b5b0ce2c3dd

commit dce5056197537fe6cb55976cc7995b5b0ce2c3dd
Author: Matt Menke <mmenke@chromium.org>
Date: Wed Jan 03 19:16:57 2018

Make NetworkContext wait until on-disk prefs have been cleared.

Previously, NetworkContext::ClearNetworkingHistorySince would tell
HttpServerProperties to clear data, and then immediately inform the
caller that the data was cleared. The data was deleted from memory by
that point, but hadn't been written to disk, and we didn't even trigger
a flush to disk, at that point.

This CL makes changes that. We now pass in the callback to the
HttpServerProperties, which writes the data to the pref store and
then tells the pref store to flush data to disk. Only once the newly
cleared data has been flushed do we invoke the callback passed to
NetworkContext::ClearNetworkingHistorySince.

Bug:  795877 
Cq-Include-Trybots: master.tryserver.chromium.android:android_cronet_tester;master.tryserver.chromium.linux:linux_mojo;master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I4b1ed23eb5bdbab77871c79cdd068b95c0972535
Reviewed-on: https://chromium-review.googlesource.com/834393
Reviewed-by: Andrei Kapishnikov <kapishnikov@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Reviewed-by: Ryan Hamilton <rch@chromium.org>
Commit-Queue: Matt Menke <mmenke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#526762}
[modify] https://crrev.com/dce5056197537fe6cb55976cc7995b5b0ce2c3dd/components/cronet/cronet_prefs_manager.cc
[modify] https://crrev.com/dce5056197537fe6cb55976cc7995b5b0ce2c3dd/content/network/http_server_properties_pref_delegate.cc
[modify] https://crrev.com/dce5056197537fe6cb55976cc7995b5b0ce2c3dd/content/network/http_server_properties_pref_delegate.h
[modify] https://crrev.com/dce5056197537fe6cb55976cc7995b5b0ce2c3dd/content/network/network_context.cc
[modify] https://crrev.com/dce5056197537fe6cb55976cc7995b5b0ce2c3dd/ios/chrome/browser/browser_state/chrome_browser_state_impl_io_data.mm
[modify] https://crrev.com/dce5056197537fe6cb55976cc7995b5b0ce2c3dd/ios/chrome/browser/net/http_server_properties_manager_factory.cc
[modify] https://crrev.com/dce5056197537fe6cb55976cc7995b5b0ce2c3dd/ios/chrome/browser/net/http_server_properties_manager_factory.h
[modify] https://crrev.com/dce5056197537fe6cb55976cc7995b5b0ce2c3dd/net/http/http_server_properties.h
[modify] https://crrev.com/dce5056197537fe6cb55976cc7995b5b0ce2c3dd/net/http/http_server_properties_impl.cc
[modify] https://crrev.com/dce5056197537fe6cb55976cc7995b5b0ce2c3dd/net/http/http_server_properties_impl.h
[modify] https://crrev.com/dce5056197537fe6cb55976cc7995b5b0ce2c3dd/net/http/http_server_properties_impl_unittest.cc
[modify] https://crrev.com/dce5056197537fe6cb55976cc7995b5b0ce2c3dd/net/http/http_server_properties_manager.cc
[modify] https://crrev.com/dce5056197537fe6cb55976cc7995b5b0ce2c3dd/net/http/http_server_properties_manager.h
[modify] https://crrev.com/dce5056197537fe6cb55976cc7995b5b0ce2c3dd/net/http/http_server_properties_manager_unittest.cc