IDL: make optional arguments (without default) explicit sometimes

Source/core/css/CSSStyleSheet.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2012 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 316 matching lines @@
         return 0;
     }
     if (!m_childRuleCSSOMWrappers.isEmpty())
         m_childRuleCSSOMWrappers.insert(index, RefPtrWillBeMember<CSSRule>(nullptr));
 
     return index;
 }
 
 unsigned CSSStyleSheet::insertRule(const String& rule, ExceptionState& exceptionState)
 {
-    UseCounter::countDeprecation(callingExecutionContext(V8PerIsolateData::mainThreadIsolate()), UseCounter::CSSStyleSheetInsertRuleOptionalArg);
     return insertRule(rule, 0, exceptionState);
 }
 
 void CSSStyleSheet::deleteRule(unsigned index, ExceptionState& exceptionState)
 {
     ASSERT(m_childRuleCSSOMWrappers.isEmpty() || m_childRuleCSSOMWrappers.size() == m_contents->ruleCount());
 
     if (index >= length()) {
         exceptionState.throwDOMException(IndexSizeError, "The index provided (" + String::number(index) + ") is larger than the maximum index (" + String::number(length() - 1) + ").");
         return;
     }
     RuleMutationScope mutationScope(this);
 
     m_contents->wrapperDeleteRule(index);
 
     if (!m_childRuleCSSOMWrappers.isEmpty()) {
         if (m_childRuleCSSOMWrappers[index])
             m_childRuleCSSOMWrappers[index]->setParentStyleSheet(0);
         m_childRuleCSSOMWrappers.remove(index);
     }
 }
 
-int CSSStyleSheet::addRule(const String& selector, const String& style, int index, ExceptionState& exceptionState)
+int CSSStyleSheet::addRule(const String& selector, const String& style, Optional<int> index, ExceptionState& exceptionState)
 {
     StringBuilder text;
     text.append(selector);
     text.appendLiteral(" { ");
     text.append(style);
     if (!style.isEmpty())
         text.append(' ');
     text.append('}');
-    insertRule(text.toString(), index, exceptionState);
+    insertRule(text.toString(), index.isMissing() ? length() : index.get(), exceptionState);
 
     // As per Microsoft documentation, always return -1.
     return -1;
 }
 
-int CSSStyleSheet::addRule(const String& selector, const String& style, ExceptionState& exceptionState)
-{
-    return addRule(selector, style, length(), exceptionState);
-}
-
 
 PassRefPtrWillBeRawPtr<CSSRuleList> CSSStyleSheet::cssRules()
 {
     if (!canAccessRules())
         return nullptr;
     if (!m_ruleListCSSOMWrapper)
         m_ruleListCSSOMWrapper = StyleSheetCSSRuleList::create(this);
     return m_ruleListCSSOMWrapper.get();
 }
 
@@ skipping 72 matching lines @@
     visitor->trace(m_mediaQueries);
     visitor->trace(m_ownerNode);
     visitor->trace(m_ownerRule);
     visitor->trace(m_mediaCSSOMWrapper);
     visitor->trace(m_childRuleCSSOMWrappers);
     visitor->trace(m_ruleListCSSOMWrapper);
     StyleSheet::trace(visitor);
 }
 
 }