[Sync] Minor refactor around SyncCycle and ModelTypeSet usage.

components/sync/engine_impl/get_updates_delegate.cc

 // Copyright 2014 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/engine_impl/get_updates_delegate.h"
 
 #include "components/sync/engine_impl/directory_update_handler.h"
 #include "components/sync/engine_impl/events/configure_get_updates_request_event.h"
 #include "components/sync/engine_impl/events/normal_get_updates_request_event.h"
 #include "components/sync/engine_impl/events/poll_get_updates_request_event.h"
 #include "components/sync/engine_impl/get_updates_processor.h"
 
 namespace syncer {
 
 namespace {
 
-void NonPassiveApplyUpdates(ModelTypeSet gu_types,
+void NonPassiveApplyUpdates(const ModelTypeSet& gu_types,
                             StatusController* status_controller,
                             UpdateHandlerMap* update_handler_map) {
   for (const auto& kv : *update_handler_map) {
     if (gu_types.Has(kv.first)) {
       kv.second->ApplyUpdates(status_controller);
     }
   }
 }
 
-void PassiveApplyUpdates(ModelTypeSet gu_types,
+void PassiveApplyUpdates(const ModelTypeSet& gu_types,
                          StatusController* status_controller,
                          UpdateHandlerMap* update_handler_map) {
   for (const auto& kv : *update_handler_map) {
     if (gu_types.Has(kv.first)) {
       kv.second->PassiveApplyUpdates(status_controller);
     }
   }
 }
 
 }  // namespace
@@ skipping 34 matching lines @@
     DCHECK(!nudge_tracker_.IsTypeBlocked(type))
         << "Throttled types should have been removed from the request_types.";
 
     nudge_tracker_.SetLegacyNotificationHint(type, progress_marker);
     nudge_tracker_.FillProtoMessage(
         type, progress_marker->mutable_get_update_triggers());
   }
 }
 
 void NormalGetUpdatesDelegate::ApplyUpdates(
-    ModelTypeSet gu_types,
+    const ModelTypeSet& gu_types,
     StatusController* status_controller,
     UpdateHandlerMap* update_handler_map) const {
   NonPassiveApplyUpdates(gu_types, status_controller, update_handler_map);
 }
 
 std::unique_ptr<ProtocolEvent> NormalGetUpdatesDelegate::GetNetworkRequestEvent(
     base::Time timestamp,
     const sync_pb::ClientToServerMessage& request) const {
   return std::unique_ptr<ProtocolEvent>(
       new NormalGetUpdatesRequestEvent(timestamp, nudge_tracker_, request));
 }
 
 ConfigureGetUpdatesDelegate::ConfigureGetUpdatesDelegate(
     sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source)
     : source_(source) {}
 
 ConfigureGetUpdatesDelegate::~ConfigureGetUpdatesDelegate() {}
 
 void ConfigureGetUpdatesDelegate::HelpPopulateGuMessage(
     sync_pb::GetUpdatesMessage* get_updates) const {
   get_updates->mutable_caller_info()->set_source(source_);
   get_updates->set_get_updates_origin(ConvertConfigureSourceToOrigin(source_));
 }
 
 void ConfigureGetUpdatesDelegate::ApplyUpdates(
-    ModelTypeSet gu_types,
+    const ModelTypeSet& gu_types,
     StatusController* status_controller,
     UpdateHandlerMap* update_handler_map) const {
   PassiveApplyUpdates(gu_types, status_controller, update_handler_map);
 }
 
 std::unique_ptr<ProtocolEvent>
 ConfigureGetUpdatesDelegate::GetNetworkRequestEvent(
     base::Time timestamp,
     const sync_pb::ClientToServerMessage& request) const {
   return std::unique_ptr<ProtocolEvent>(new ConfigureGetUpdatesRequestEvent(
@@ skipping 29 matching lines @@
     sync_pb::GetUpdatesMessage* get_updates) const {
   // Set legacy GetUpdatesMessage.GetUpdatesCallerInfo information.
   get_updates->mutable_caller_info()->set_source(
       sync_pb::GetUpdatesCallerInfo::PERIODIC);
 
   // Set the new and improved version of source, too.
   get_updates->set_get_updates_origin(sync_pb::SyncEnums::PERIODIC);
 }
 
 void PollGetUpdatesDelegate::ApplyUpdates(
-    ModelTypeSet gu_types,
+    const ModelTypeSet& gu_types,
     StatusController* status_controller,
     UpdateHandlerMap* update_handler_map) const {
   NonPassiveApplyUpdates(gu_types, status_controller, update_handler_map);
 }
 
 std::unique_ptr<ProtocolEvent> PollGetUpdatesDelegate::GetNetworkRequestEvent(
     base::Time timestamp,
     const sync_pb::ClientToServerMessage& request) const {
   return std::unique_ptr<ProtocolEvent>(
       new PollGetUpdatesRequestEvent(timestamp, request));
 }
 
 }  // namespace syncer