[Sync] Use a proto to generate AutofillSyncStorageKey's storage keys.

components/autofill/core/browser/webdata/autocomplete_sync_bridge.h

 // Copyright 2016 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.
 
 #ifndef COMPONENTS_AUTOFILL_CORE_BROWSER_WEBDATA_AUTOCOMPLETE_SYNC_BRIDGE_H_
 #define COMPONENTS_AUTOFILL_CORE_BROWSER_WEBDATA_AUTOCOMPLETE_SYNC_BRIDGE_H_
 
+#include <memory>
+#include <string>
+
 #include "base/scoped_observer.h"
 #include "base/supports_user_data.h"
 #include "base/threading/non_thread_safe.h"
 #include "components/autofill/core/browser/webdata/autofill_change.h"
 #include "components/autofill/core/browser/webdata/autofill_webdata_service_observer.h"
 #include "components/sync/model/metadata_change_list.h"
 #include "components/sync/model/model_type_sync_bridge.h"
 
 namespace syncer {
 class SyncError;
@@ skipping 65 matching lines @@
   // SupportsUserData, so it's guaranteed to outlive |this|.
   AutofillWebDataBackend* const web_data_backend_;
 
   ScopedObserver<AutofillWebDataBackend, AutocompleteSyncBridge>
       scoped_observer_;
 };
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_CORE_BROWSER_WEBDATA_AUTOCOMPLETE_SYNC_BRIDGE_H_