Introduce update_client::NetworkFetcher as a way to abstract the network.

This is a mechanical change and work in progress.

The goal here is to decouple update client from its Chrome network
dependencies such as //net and //services/network.

This change avoids inejction of a direct dependency of the servicified
network stack in favor of injecting a NetworkFetcherFactory, which
in turns can create instances of NetworkFetcher, where they are needed.

The next change will further isolate the implementation dependencies on
the Chrome network, and allow for selecting different implementations
of the NetworkFetcher.


Bug: 929167
Change-Id: I14aff38dd7bddd5d3d6b4c1af52ccb57a06552a9
Reviewed-on: https://chromium-review.googlesource.com/c/1461337
Reviewed-by: Sylvain Defresne <[email protected]>
Reviewed-by: Martin Šrámek <[email protected]>
Reviewed-by: Minh Nguyen <[email protected]>
Reviewed-by: Joshua Pawlicki <[email protected]>
Commit-Queue: Sorin Jianu <[email protected]>
Cr-Commit-Position: refs/heads/master@{#631250}
diff --git a/components/component_updater/configurator_impl.cc b/components/component_updater/configurator_impl.cc
index 2a964f7..86f70034 100644
--- a/components/component_updater/configurator_impl.cc
+++ b/components/component_updater/configurator_impl.cc
@@ -8,6 +8,7 @@
 
 #include <algorithm>
 
+#include "base/callback.h"
 #include "base/feature_list.h"
 #include "base/stl_util.h"
 #include "base/strings/string_split.h"