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

Source/core/frame/UseCounter.cpp

 /*
  * Copyright (C) 2012 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 859 matching lines @@
 
     case SVGSVGElementUnsuspendRedraw:
         return "'SVGSVGElement.unsuspendRedraw()' is deprecated, please do not use it. It is a no-op, as per SVG2 (https://svgwg.org/svg2-draft/struct.html#__svg__SVGSVGElement__unsuspendRedraw).";
 
     case SVGSVGElementUnsuspendRedrawAll:
         return "'SVGSVGElement.unsuspendRedrawAll()' is deprecated, please do not use it. It is a no-op, as per SVG2 (https://svgwg.org/svg2-draft/struct.html#__svg__SVGSVGElement__unsuspendRedrawAll).";
 
     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.";
-
     // Powerful features on insecure origins (https://goo.gl/rStTGz)
     case GeolocationInsecureOrigin:
         return "getCurrentPosition() and watchPosition() are deprecated on insecure origins, and support will be removed in the future. You should consider switching your application to a secure origin, such as HTTPS. See https://goo.gl/rStTGz for more details.";
 
     case GetUserMediaInsecureOrigin:
         return "getUserMedia() is deprecated on insecure origins, and support will be removed in the future. You should consider switching your application to a secure origin, such as HTTPS. See https://goo.gl/rStTGz for more details.";
 
     case FullscreenInsecureOrigin:
         return "requestFullscreen() is deprecated on insecure origins, and support will be removed in the future. You should consider switching your application to a secure origin, such as HTTPS. See https://goo.gl/rStTGz for more details.";
 
@@ skipping 52 matching lines @@
 UseCounter* UseCounter::getFrom(const StyleSheetContents* sheetContents)
 {
     // FIXME: We may want to handle stylesheets that have multiple owners
     //        http://crbug.com/242125
     if (sheetContents && sheetContents->hasSingleOwnerNode())
         return getFrom(sheetContents->singleOwnerDocument());
     return 0;
 }
 
 } // namespace blink