Remove CSSCharsetRule

Source/core/css/CSSGroupingRule.cpp

Index: Source/core/css/CSSGroupingRule.cpp
diff --git a/Source/core/css/CSSGroupingRule.cpp b/Source/core/css/CSSGroupingRule.cpp
index b19fe9a16380cdbea5c65fa7d5c16992365d09dd..d4138f42d55b749a16d61465c10f390881f18283 100644
--- a/Source/core/css/CSSGroupingRule.cpp
+++ b/Source/core/css/CSSGroupingRule.cpp
@@ -77,9 +77,8 @@ unsigned CSSGroupingRule::insertRule(const String& ruleString, unsigned index, E
     }
 
     if (newRule->isImportRule()) {
-        // FIXME: an HierarchyRequestError should also be thrown for a @charset or a nested
-        // @media rule. They are currently not getting parsed, resulting in a SyntaxError
-        // to get raised above.
+        // FIXME: an HierarchyRequestError should also be thrown for a nested @media rule. They are
+        // currently not getting parsed, resulting in a SyntaxError to get raised above.
         exceptionState.throwDOMException(HierarchyRequestError, "'@import' rules cannot be inserted inside a group rule.");
         return 0;
     }