update_engine: Switch to chrome-dbus for client requests in update_engine

update_engine daemon acts as DBus client to send DBus calls to shill,
power_manager and chrome, and to listen for signals from shill, chrome
and login_manager. This patch migrates these calls and signals to use
chrome-dbus framework instead of dbus-glib.

All references to dbus-glib code are removed.

BUG=chromium:419827
TEST=Updated unittest. Deployed on a link device and tested interactions with shill and chromium.

Change-Id: I31b389e0d1690cccb115ff3b6539c876ba81bd0e
Reviewed-on: https://chromium-review.googlesource.com/290990
Tested-by: Alex Deymo <deymo@chromium.org>
Reviewed-by: Alex Deymo <deymo@chromium.org>
Commit-Queue: Alex Deymo <deymo@chromium.org>
Trybot-Ready: Alex Deymo <deymo@chromium.org>
diff --git a/update_manager/state_factory.h b/update_manager/state_factory.h
index fa1164c..fd37ea7 100644
--- a/update_manager/state_factory.h
+++ b/update_manager/state_factory.h
@@ -5,7 +5,8 @@
 #ifndef UPDATE_ENGINE_UPDATE_MANAGER_STATE_FACTORY_H_
 #define UPDATE_ENGINE_UPDATE_MANAGER_STATE_FACTORY_H_
 
-#include "update_engine/dbus_wrapper_interface.h"
+#include "update_engine/dbus_proxies.h"
+#include "update_engine/shill_proxy.h"
 #include "update_engine/system_state.h"
 #include "update_engine/update_manager/state.h"
 
@@ -18,7 +19,8 @@
 // to initialize.
 State* DefaultStateFactory(
     policy::PolicyProvider* policy_provider,
-    chromeos_update_engine::DBusWrapperInterface* dbus,
+    chromeos_update_engine::ShillProxy* shill_proxy,
+    org::chromium::SessionManagerInterfaceProxyInterface* session_manager_proxy,
     chromeos_update_engine::SystemState* system_state);
 
 }  // namespace chromeos_update_manager