[Sync] Refactor sync manager into interface.

sync/internal_api/public/util/sync_string_conversions.cc

+// 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 "sync/internal_api/public/util/sync_string_conversions.h"
+
+namespace syncer {
+
+const char* ConnectionStatusToString(ConnectionStatus status) {
+  switch (status) {
+    case CONNECTION_OK:
+      return "CONNECTION_OK";
+    case CONNECTION_AUTH_ERROR:
+      return "CONNECTION_AUTH_ERROR";
+    case CONNECTION_SERVER_ERROR:
+      return "CONNECTION_SERVER_ERROR";
+    default:
+      NOTREACHED();
+      return "INVALID_CONNECTION_STATUS";
+  }
+}
+
+// Helper function that converts a PassphraseRequiredReason value to a string.
+const char* PassphraseRequiredReasonToString(
+    PassphraseRequiredReason reason) {
+  switch (reason) {
+    case REASON_PASSPHRASE_NOT_REQUIRED:
+      return "REASON_PASSPHRASE_NOT_REQUIRED";
+    case REASON_ENCRYPTION:
+      return "REASON_ENCRYPTION";
+    case REASON_DECRYPTION:
+      return "REASON_DECRYPTION";
+    default:
+      NOTREACHED();
+      return "INVALID_REASON";
+  }
+}
+
+}  // namespace syncer