Make ONCCertificateImporter async.

chromeos/network/onc/mock_certificate_importer.cc

Index: chromeos/network/onc/mock_certificate_importer.cc
diff --git a/chromeos/network/onc/mock_certificate_importer.cc b/chromeos/network/onc/mock_certificate_importer.cc
deleted file mode 100644
index 5ae7fb200e9a1cdea84ce7dc8c9fa6573ecd3531..0000000000000000000000000000000000000000
--- a/chromeos/network/onc/mock_certificate_importer.cc
+++ /dev/null
@@ -1,17 +0,0 @@
-// Copyright 2013 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "chromeos/network/onc/mock_certificate_importer.h"
-
-namespace chromeos {
-namespace onc {
-
-MockCertificateImporter::MockCertificateImporter() {
-}
-
-MockCertificateImporter::~MockCertificateImporter() {
-}
-
-}  // namespace onc
-}  // namespace chromeos