[Sync] Initial support for encrypting any datatype (no UI hookup yet).

chrome/browser/sync/protocol/password_specifics.proto

 // Copyright (c) 2010 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.
 //
 // Sync protocol datatype extension for password data.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 option retain_unknown_fields = true;
@@ skipping 20 matching lines @@
   optional bool blacklisted = 12;
 }
 
 // Properties of password sync objects. The actual password data is held in a
 // PasswordSpecificsData that is encrypted into |encrypted|.
 message PasswordSpecifics {
   optional EncryptedData encrypted = 1;
 }
 
 extend EntitySpecifics {
-  optional PasswordSpecifics password = 45873;
+        optional PasswordSpecifics password = 45873;
 }