update_engine: Use org.chromium.NetworkProxyService.

Make update_engine call Chrome's new
org.chromium.NetworkProxyService D-Bus service to resolve
network proxies instead of using
org.chromium.LibCrosService. The new service supports
asynchronous replies instead of responding via D-Bus
signals.

BUG=chromium:446115,chromium:703217
TEST=unit tests pass; also added debug logging and verified
     that chrome's proxy settings are used

Change-Id: Iebd268ea3e551c0760416d955828b9d7ebf851fb
Reviewed-on: https://chromium-review.googlesource.com/497491
Commit-Ready: Dan Erat <derat@chromium.org>
Tested-by: Dan Erat <derat@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>
diff --git a/update_manager/state_factory.h b/update_manager/state_factory.h
index 726deeb..c8db776 100644
--- a/update_manager/state_factory.h
+++ b/update_manager/state_factory.h
@@ -23,9 +23,11 @@
 #include "update_engine/system_state.h"
 #include "update_engine/update_manager/state.h"
 
-namespace chromeos_update_engine {
-class LibCrosProxy;
-}
+namespace org {
+namespace chromium {
+class LibCrosServiceInterfaceProxyInterface;
+}  // namespace chromium
+}  // namespace org
 
 namespace chromeos_update_manager {
 
@@ -38,7 +40,7 @@
     policy::PolicyProvider* policy_provider,
     chromeos_update_engine::ShillProxy* shill_proxy,
     org::chromium::SessionManagerInterfaceProxyInterface* session_manager_proxy,
-    chromeos_update_engine::LibCrosProxy* libcros_proxy,
+    org::chromium::LibCrosServiceInterfaceProxyInterface* libcros_proxy,
     chromeos_update_engine::SystemState* system_state);
 
 }  // namespace chromeos_update_manager