[Sync] Pass ModelTypeSet by value everywhere

sync/engine/all_status.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 "sync/engine/all_status.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/port.h"
@@ skipping 121 matching lines @@
 void AllStatus::IncrementNotificationsReceived() {
   ScopedStatusLock lock(this);
   ++status_.notifications_received;
 }
 
 void AllStatus::SetEncryptedTypes(ModelTypeSet types) {
   ScopedStatusLock lock(this);
   status_.encrypted_types = types;
 }
 
-void AllStatus::SetThrottledTypes(const ModelTypeSet& types) {
+void AllStatus::SetThrottledTypes(ModelTypeSet types) {
   ScopedStatusLock lock(this);
   status_.throttled_types = types;
 }
 
 void AllStatus::SetCryptographerReady(bool ready) {
   ScopedStatusLock lock(this);
   status_.cryptographer_ready = ready;
 }
 
 void AllStatus::SetCryptoHasPendingKeys(bool has_pending_keys) {
   ScopedStatusLock lock(this);
   status_.crypto_has_pending_keys = has_pending_keys;
 }
 
 void AllStatus::SetUniqueId(const std::string& guid) {
   ScopedStatusLock lock(this);
   status_.unique_id = guid;
 }
 
 ScopedStatusLock::ScopedStatusLock(AllStatus* allstatus)
     : allstatus_(allstatus) {
   allstatus->mutex_.Acquire();
 }
 
 ScopedStatusLock::~ScopedStatusLock() {
   allstatus_->mutex_.Release();
 }
 
 }  // namespace syncer