Make UpdateAttempter own debugd_proxy.

It's the only class using this proxy.

Test: mma
Bug: 28800946

Change-Id: I1a98b417f213db5d47de451390367ca4975db4b0
diff --git a/real_system_state.cc b/real_system_state.cc
index 16d8876..70bef8c 100644
--- a/real_system_state.cc
+++ b/real_system_state.cc
@@ -37,9 +37,6 @@
 
 namespace chromeos_update_engine {
 
-RealSystemState::RealSystemState(const scoped_refptr<dbus::Bus>& bus)
-    : debugd_proxy_(bus) {}
-
 RealSystemState::~RealSystemState() {
   // Prevent any DBus communication from UpdateAttempter when shutting down the
   // daemon.
@@ -134,8 +131,7 @@
 
   // Initialize the UpdateAttempter before the UpdateManager.
   update_attempter_.reset(
-      new UpdateAttempter(this, certificate_checker_.get(), &libcros_proxy_,
-                          &debugd_proxy_));
+      new UpdateAttempter(this, certificate_checker_.get(), &libcros_proxy_));
   update_attempter_->Init();
 
   weave_service_ = ConstructWeaveService(update_attempter_.get());