[Autofill] Sync new wallet metadata fields through Chrome Sync.

components/sync/protocol/autofill_specifics.proto

 // 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.
 //
 // Sync protocol datatype extension for autofill.
 
 // Update proto_value_conversions{.h,.cc,_unittest.cc} if you change
 // any fields in this file.
 
 syntax = "proto2";
@@ skipping 191 matching lines @@
   // - Phone number
   // - Language code
   optional string id = 2;
 
   // The number of times that this Wallet card or address was used.
   optional int64 use_count = 3;
 
   // The last use date of this Wallet card or address. Measured in microseconds
   // since the Windows epoch (1601).
   optional int64 use_date = 4;
+
+  // The id of the profile/address that represents the billing address of this
+  // Wallet card.
+  optional string card_billing_address_id = 5;
+
+  // Whether this Wallet address has been converted to a local autofill profile.
+  optional bool address_has_converted = 6;
 }