[Sync] Replacing NULL with nullptr in code and null in comments for components/sync/

components/sync/base/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/base/sync_prefs.h"
 
 #include "base/base64.h"
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/values.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/prefs/pref_service.h"
 #include "components/sync/base/pref_names.h"
 
 namespace syncer {
 
 SyncPrefObserver::~SyncPrefObserver() {}
 
 SyncPrefs::SyncPrefs(PrefService* pref_service) : pref_service_(pref_service) {
   DCHECK(pref_service);
   RegisterPrefGroups();
   // Watch the preference that indicates sync is managed so we can take
   // appropriate action.
   pref_sync_managed_.Init(
       prefs::kSyncManaged, pref_service_,
       base::Bind(&SyncPrefs::OnSyncManagedPrefChanged, base::Unretained(this)));
 }
 
-SyncPrefs::SyncPrefs() : pref_service_(NULL) {}
+SyncPrefs::SyncPrefs() : pref_service_(nullptr) {}
 
 SyncPrefs::~SyncPrefs() {
   DCHECK(CalledOnValidThread());
 }
 
 // static
 void SyncPrefs::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterBooleanPref(prefs::kSyncFirstSetupComplete, false);
   registry->RegisterBooleanPref(prefs::kSyncSuppressStart, false);
@@ skipping 277 matching lines @@
     case ARC_PACKAGE:
       return prefs::kSyncArcPackage;
     case PRINTERS:
       return prefs::kSyncPrinters;
     case READING_LIST:
       return prefs::kSyncReadingList;
     default:
       break;
   }
   NOTREACHED() << "Type is " << data_type;
-  return NULL;
+  return nullptr;
 }
 
 #if defined(OS_CHROMEOS)
 std::string SyncPrefs::GetSpareBootstrapToken() const {
   DCHECK(CalledOnValidThread());
   return pref_service_->GetString(prefs::kSyncSpareBootstrapToken);
 }
 
 void SyncPrefs::SetSpareBootstrapToken(const std::string& token) {
   DCHECK(CalledOnValidThread());
@@ skipping 61 matching lines @@
   if (!pref_name) {
     NOTREACHED();
     return false;
   }
 
   // Device info is always enabled.
   if (pref_name == prefs::kSyncDeviceInfo)
     return true;
 
   if (type == PROXY_TABS &&
-      pref_service_->GetUserPrefValue(pref_name) == NULL &&
+      pref_service_->GetUserPrefValue(pref_name) == nullptr &&
       pref_service_->IsUserModifiablePreference(pref_name)) {
     // If there is no tab sync preference yet (i.e. newly enabled type),
     // default to the session sync preference value.
     pref_name = GetPrefNameForDataType(SESSIONS);
   }
 
   return pref_service_->GetBoolean(pref_name);
 }
 
 void SyncPrefs::SetDataTypePreferred(ModelType type, bool is_preferred) {
@@ skipping 120 matching lines @@
     sync_pb::NigoriSpecifics* nigori_specifics) const {
   const std::string encoded =
       pref_service_->GetString(prefs::kSyncNigoriStateForPassphraseTransition);
   std::string decoded;
   if (base::Base64Decode(encoded, &decoded)) {
     nigori_specifics->ParseFromString(decoded);
   }
 }
 
 }  // namespace syncer