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

components/sync/test/engine/mock_connection_manager.cc

 // Copyright 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.
 //
 // Mock ServerConnectionManager class for use in client regression tests.
 
 #include "components/sync/test/engine/mock_connection_manager.h"
 
 #include <map>
 
@@ skipping 27 matching lines @@
     : ServerConnectionManager("unused", 0, false, signal),
       server_reachable_(true),
       conflict_all_commits_(false),
       conflict_n_commits_(0),
       next_new_id_(10000),
       store_birthday_("Store BDay!"),
       store_birthday_sent_(false),
       client_stuck_(false),
       countdown_to_postbuffer_fail_(0),
       directory_(directory),
-      mid_commit_observer_(NULL),
+      mid_commit_observer_(nullptr),
       throttling_(false),
       partialThrottling_(false),
       fail_non_periodic_get_updates_(false),
       next_position_in_parent_(2),
       use_legacy_bookmarks_protocol_(false),
       num_get_updates_requests_(0) {
   SetNewTimestamp(0);
   SetAuthToken(kValidAuthToken);
 }
 
@@ skipping 673 matching lines @@
 MockConnectionManager::GetProgressMarkerForType(
     const google::protobuf::RepeatedPtrField<sync_pb::DataTypeProgressMarker>&
         filter,
     ModelType value) {
   int data_type_id = GetSpecificsFieldNumberFromModelType(value);
   for (int i = 0; i < filter.size(); ++i) {
     if (filter.Get(i).data_type_id() == data_type_id) {
       return &(filter.Get(i));
     }
   }
-  return NULL;
+  return nullptr;
 }
 
 void MockConnectionManager::SetServerReachable() {
   server_reachable_ = true;
 }
 
 void MockConnectionManager::SetServerNotReachable() {
   server_reachable_ = false;
 }
 
 void MockConnectionManager::UpdateConnectionStatus() {
   if (!server_reachable_) {
     server_status_ = HttpResponse::CONNECTION_UNAVAILABLE;
   } else {
     server_status_ = HttpResponse::SERVER_CONNECTION_OK;
   }
 }
 
 void MockConnectionManager::SetServerStatus(
     HttpResponse::ServerConnectionCode server_status) {
   server_status_ = server_status;
 }
 
 }  // namespace syncer