[cros] Use mocked URLFetcher and other mocks in ExistingUserController tests.

chrome/browser/chromeos/login/mock_login_utils.cc

Index: chrome/browser/chromeos/login/mock_login_utils.cc
diff --git a/chrome/browser/chromeos/login/mock_login_utils.cc b/chrome/browser/chromeos/login/mock_login_utils.cc
new file mode 100644
index 0000000000000000000000000000000000000000..65cb7a6d4ec1d7c35c37b26bffc0f79ed5bbf0ac
--- /dev/null
+++ b/chrome/browser/chromeos/login/mock_login_utils.cc
@@ -0,0 +1,13 @@
+// Copyright (c) 2012 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 "chrome/browser/chromeos/login/mock_login_utils.h"
+
+namespace chromeos {
+
+MockLoginUtils::MockLoginUtils() {}
+
+MockLoginUtils::~MockLoginUtils() {}
+
+}  // namespace chromeos