[Sync] Implement keystore migration support.

sync/protocol/proto_enum_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.
 
 // Keep this file in sync with the .proto files in this directory.
 
 #include "sync/protocol/proto_enum_conversions.h"
 
 #include "base/basictypes.h"
 #include "base/logging.h"
@@ skipping 149 matching lines @@
     sync_pb::SessionTab::FaviconType favicon_type) {
   ASSERT_ENUM_BOUNDS(sync_pb::SessionTab, FaviconType, TYPE_WEB_FAVICON,
                      TYPE_WEB_FAVICON);
   switch (favicon_type) {
     ENUM_CASE(sync_pb::SessionTab, TYPE_WEB_FAVICON);
   }
   NOTREACHED();
   return "";
 }
 
+const char* PassphraseTypeString(
+    sync_pb::NigoriSpecifics::PassphraseType type) {
+  ASSERT_ENUM_BOUNDS(sync_pb::NigoriSpecifics, PassphraseType,
+                     IMPLICIT_PASSPHRASE, CUSTOM_PASSPHRASE);
+  switch (type) {
+    ENUM_CASE(sync_pb::NigoriSpecifics, IMPLICIT_PASSPHRASE);
+    ENUM_CASE(sync_pb::NigoriSpecifics, KEYSTORE_PASSPHRASE);
+    ENUM_CASE(sync_pb::NigoriSpecifics, FROZEN_IMPLICIT_PASSPHRASE);
+    ENUM_CASE(sync_pb::NigoriSpecifics, CUSTOM_PASSPHRASE);
+  }
+  NOTREACHED();
+  return "";
+}
+
 #undef ASSERT_ENUM_BOUNDS
 #undef ENUM_CASE
 
 }  // namespace syncer