Remove Attr child nodes (making Attr a Node, not a ContainerNode)

Source/core/frame/UseCounter.cpp

Index: Source/core/frame/UseCounter.cpp
diff --git a/Source/core/frame/UseCounter.cpp b/Source/core/frame/UseCounter.cpp
index 3c734e64fe73e7d161c08694e6bd2915f5e1aa52..7cb7263f2fc1fc221f34380071523f4676d4040a 100644
--- a/Source/core/frame/UseCounter.cpp
+++ b/Source/core/frame/UseCounter.cpp
@@ -877,10 +877,6 @@ String UseCounter::deprecationMessage(Feature feature)
     case ServiceWorkerClientPostMessage:
         return "'Client.postMessage()' is an experimental API and may change. See https://github.com/slightlyoff/ServiceWorker/issues/609.";
 
-    case AttrChildAccess:
-    case AttrChildChange:
-        return "Attr child nodes are deprecated and will be removed in M45, around August 2015. Please use 'Attr.value' instead.";
-
     case CSSKeyframesRuleInsertRule:
         return "'CSSKeyframesRule.insertRule()' is deprecated and will be removed in M45, around August 2015. Please use 'CSSKeyframesRule.appendRule()' instead.";