dbus: Make Bus::GetManagedObjects skip unavailable services.

dbus/object_manager.cc

Index: dbus/object_manager.cc
diff --git a/dbus/object_manager.cc b/dbus/object_manager.cc
index 56143c758b4bb9b40f72e0f55075e0caa1f77ddc..330a161a547bb706da7d2ad4e72dbf6f7b8811e2 100644
--- a/dbus/object_manager.cc
+++ b/dbus/object_manager.cc
@@ -147,6 +147,10 @@ void ObjectManager::GetManagedObjects() {
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
+bool ObjectManager::ServiceIsAvailable() {
+  return object_proxy_->ServiceIsAvailable();
+}
+
 void ObjectManager::CleanUp() {
   DCHECK(bus_);
   bus_->AssertOnDBusThread();