dbus/values_util.h: Add functions to append collection type values to message.

chromeos/dbus/nfc_device_client.cc

Index: chromeos/dbus/nfc_device_client.cc
diff --git a/chromeos/dbus/nfc_device_client.cc b/chromeos/dbus/nfc_device_client.cc
index e9833c96cfe28815c4bb56bd3ad0b625c2e476bf..a1976c8119ac3531684f031e10b4b216589993ca 100644
--- a/chromeos/dbus/nfc_device_client.cc
+++ b/chromeos/dbus/nfc_device_client.cc
@@ -11,6 +11,7 @@
 #include "chromeos/dbus/nfc_adapter_client.h"
 #include "dbus/bus.h"
 #include "dbus/message.h"
+#include "dbus/values_util.h"
 #include "third_party/cros_system_api/dbus/service_constants.h"
 
 using chromeos::nfc_client_helpers::DBusObjectMap;
@@ -108,18 +109,7 @@ class NfcDeviceClientImpl : public NfcDeviceClient,
     dbus::MethodCall method_call(nfc_device::kNfcDeviceInterface,
                                  nfc_device::kPush);
     dbus::MessageWriter writer(&method_call);
-    dbus::MessageWriter array_writer(NULL);
-    dbus::MessageWriter dict_entry_writer(NULL);
-    writer.OpenArray("{sv}", &array_writer);
-    for (base::DictionaryValue::Iterator iter(attributes);
-         !iter.IsAtEnd(); iter.Advance()) {
-      array_writer.OpenDictEntry(&dict_entry_writer);
-      dict_entry_writer.AppendString(iter.key());
-      nfc_client_helpers::AppendValueDataAsVariant(&dict_entry_writer,
-                                                   iter.value());
-      array_writer.CloseContainer(&dict_entry_writer);
-    }
-    writer.CloseContainer(&array_writer);
+    dbus::AppendValueData(&writer, attributes);
 
     object_proxy->CallMethodWithErrorCallback(
         &method_call,