Support for CSSOM CSSNamespaceRule interface

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 274 matching lines @@
 {
     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()) + ").");
         return 0;
     }
     CSSParserContext context(m_contents->parserContext(), UseCounter::getFrom(this));
     RefPtrWillBeRawPtr<StyleRuleBase> rule = CSSParser::parseRule(context, m_contents.get(), ruleString);
 
-    // FIXME: @namespace rules have special handling in the CSSOM spec, but it
-    // mostly doesn't make sense since we don't support CSSNamespaceRule
-    if (!rule || rule->isNamespaceRule()) {
+    if (!rule) {
         exceptionState.throwDOMException(SyntaxError, "Failed to parse the rule '" + ruleString + "'.");
         return 0;
     }
     RuleMutationScope mutationScope(this);
 
     bool success = m_contents->wrapperInsertRule(rule, index);
     if (!success) {
-        exceptionState.throwDOMException(HierarchyRequestError, "Failed to insert the rule.");
+        if (rule->isNamespaceRule())
+            exceptionState.throwDOMException(InvalidStateError, "Failed to insert the rule");
+        else
+            exceptionState.throwDOMException(HierarchyRequestError, "Failed to insert the rule.");
         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);
+    bool success = m_contents->wrapperDeleteRule(index);
+    if (!success) {
+        exceptionState.throwDOMException(InvalidStateError, "Failed to delete rule");
+        return;
+    }
 
     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)
 {
@@ skipping 105 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);
 }
 
 } // namespace blink