Rewrite scoped_ptr<T>(NULL) to use the default ctor in chromeos/.

chromeos/dbus/ibus/ibus_object.cc

Index: chromeos/dbus/ibus/ibus_object.cc
diff --git a/chromeos/dbus/ibus/ibus_object.cc b/chromeos/dbus/ibus/ibus_object.cc
index 96a5fa4d3e609fa8edb16f2bc40f53d1e2a04d96..f7cf4f770e7e920e89f162800e94b69b69b394bc 100644
--- a/chromeos/dbus/ibus/ibus_object.cc
+++ b/chromeos/dbus/ibus/ibus_object.cc
@@ -19,10 +19,7 @@ IBusObjectReader::IBusObjectReader(const std::string& type_name,
                                    dbus::MessageReader* reader)
     : type_name_(type_name),
       original_reader_(reader),
-      top_variant_reader_(NULL),
-      contents_reader_(NULL),
-      check_result_(IBUS_OBJECT_NOT_CHECKED) {
-}
+      check_result_(IBUS_OBJECT_NOT_CHECKED) {}
 
 IBusObjectReader::~IBusObjectReader() {
   for (std::map<std::string, base::Value*>::iterator ite = attachments_.begin();