dbus: Make Bus::GetManagedObjects skip unavailable services.

dbus/bus.cc

Index: dbus/bus.cc
diff --git a/dbus/bus.cc b/dbus/bus.cc
index d6e2c5b6401459e6322d1a3d9e593d03ee9ae55e..4b853e0b2cdbf9ce70216fbd7f8bed9eb832fce0 100644
--- a/dbus/bus.cc
+++ b/dbus/bus.cc
@@ -403,7 +403,9 @@ void Bus::RemoveObjectManagerInternalHelper(
 void Bus::GetManagedObjects() {
   for (ObjectManagerTable::iterator iter = object_manager_table_.begin();
        iter != object_manager_table_.end(); ++iter) {
-    iter->second->GetManagedObjects();
+    // Don't spam the logs with D-Bus errors if the service is unavailable.
+    if (iter->second->ServiceIsAvailable())
+      iter->second->GetManagedObjects();
   }
 }