Migrate WTF::HashSet::add() to ::insert() [part 1 of N]

third_party/WebKit/Source/core/dom/DocumentParser.cpp

 /*
  * Copyright (C) 2010 Google, Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 67 matching lines @@
 void DocumentParser::detach() {
   m_state = DetachedState;
   m_document = nullptr;
 }
 
 void DocumentParser::suspendScheduledTasks() {}
 
 void DocumentParser::resumeScheduledTasks() {}
 
 void DocumentParser::addClient(DocumentParserClient* client) {
-  m_clients.add(client);
+  m_clients.insert(client);
 }
 
 void DocumentParser::removeClient(DocumentParserClient* client) {
   m_clients.remove(client);
 }
 
 }  // namespace blink