[Sync] Removing duplicated includes between cc and h files.

components/sync/driver/sync_prefs.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 "components/sync/driver/sync_prefs.h"
 
 #include "base/base64.h"
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/values.h"
-#include "build/build_config.h"
 #include "components/pref_registry/pref_registry_syncable.h"
-#include "components/prefs/pref_member.h"
 #include "components/prefs/pref_service.h"
 #include "components/sync/driver/pref_names.h"
 
 namespace sync_driver {
 
 SyncPrefObserver::~SyncPrefObserver() {}
 
 SyncPrefs::SyncPrefs(PrefService* pref_service) : pref_service_(pref_service) {
   DCHECK(pref_service);
   RegisterPrefGroups();
@@ skipping 528 matching lines @@
     return std::unique_ptr<syncer::SyncEncryptionHandler::NigoriState>();
 
   std::unique_ptr<syncer::SyncEncryptionHandler::NigoriState> result(
       new syncer::SyncEncryptionHandler::NigoriState());
   if (!result->nigori_specifics.ParseFromString(decoded))
     return std::unique_ptr<syncer::SyncEncryptionHandler::NigoriState>();
   return result;
 }
 
 }  // namespace sync_driver