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/fake_system_state.cc b/fake_system_state.cc
index c10dca1..6f1bd02 100644
--- a/fake_system_state.cc
+++ b/fake_system_state.cc
@@ -9,22 +9,22 @@
 // Mock the SystemStateInterface so that we could lie that
 // OOBE is completed even when there's no such marker file, etc.
 FakeSystemState::FakeSystemState()
-  : mock_update_attempter_(this, &dbus_),
-    mock_request_params_(this),
-    fake_update_manager_(&fake_clock_),
-    clock_(&fake_clock_),
-    connection_manager_(&mock_connection_manager_),
-    hardware_(&fake_hardware_),
-    metrics_lib_(&mock_metrics_lib_),
-    prefs_(&mock_prefs_),
-    powerwash_safe_prefs_(&mock_powerwash_safe_prefs_),
-    payload_state_(&mock_payload_state_),
-    update_attempter_(&mock_update_attempter_),
-    request_params_(&mock_request_params_),
-    p2p_manager_(&mock_p2p_manager_),
-    update_manager_(&fake_update_manager_),
-    device_policy_(nullptr),
-    fake_system_rebooted_(false) {
+    : mock_update_attempter_(this, nullptr, nullptr),
+      mock_request_params_(this),
+      fake_update_manager_(&fake_clock_),
+      clock_(&fake_clock_),
+      connection_manager_(&mock_connection_manager_),
+      hardware_(&fake_hardware_),
+      metrics_lib_(&mock_metrics_lib_),
+      prefs_(&mock_prefs_),
+      powerwash_safe_prefs_(&mock_powerwash_safe_prefs_),
+      payload_state_(&mock_payload_state_),
+      update_attempter_(&mock_update_attempter_),
+      request_params_(&mock_request_params_),
+      p2p_manager_(&mock_p2p_manager_),
+      update_manager_(&fake_update_manager_),
+      device_policy_(nullptr),
+      fake_system_rebooted_(false) {
   mock_payload_state_.Initialize(this);
   mock_update_attempter_.Init();
 }