buffet: Added unit tests for DeviceRegistrationInfo class

Added unit tests for GCD registration workflow in Buffet.

BUG=chromium:367381
TEST=Unit tests pass (old and new).

Change-Id: Ia3ad5f028ae6fc7f3d2acdf4648ceb88cc4e00ef
Reviewed-on: https://chromium-review.googlesource.com/197568
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
Reviewed-by: Christopher Wiley <wiley@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
diff --git a/buffet/device_registration_storage_keys.h b/buffet/device_registration_storage_keys.h
new file mode 100644
index 0000000..a6c9239
--- /dev/null
+++ b/buffet/device_registration_storage_keys.h
@@ -0,0 +1,31 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BUFFET_DEVICE_REGISTRATION_STORAGE_KEYS_H_
+#define BUFFET_DEVICE_REGISTRATION_STORAGE_KEYS_H_
+
+// These are the keys used to identify specific device registration information
+// being saved to a storage. Used mostly internally by DeviceRegistrationInfo
+// but also exposed so that tests can access them.
+namespace buffet {
+namespace storage_keys {
+
+// Persistent keys
+extern const char kClientId[];
+extern const char kClientSecret[];
+extern const char kApiKey[];
+extern const char kRefreshToken[];
+extern const char kDeviceId[];
+extern const char kOAuthURL[];
+extern const char kServiceURL[];
+extern const char kRobotAccount[];
+// Transient keys
+extern const char kDeviceKind[];
+extern const char kSystemName[];
+extern const char kDisplayName[];
+
+}  // namespace storage_keys
+}  // namespace buffet
+
+#endif  // BUFFET_DEVICE_REGISTRATION_STORAGE_KEYS_H_