Deprecate Attr.nodeValue / Attr.textContent

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 aef010f88308bd2631905d25ac8dc90f2e6b7f2c..ae0f32edc8b4e0f828d9421baa7147f55ba7ba22 100644
--- a/Source/core/frame/UseCounter.cpp
+++ b/Source/core/frame/UseCounter.cpp
@@ -715,6 +715,12 @@ String UseCounter::deprecationMessage(Feature feature)
     case NodeIteratorDetach:
         return "'NodeIterator.detach' is now a no-op, as per DOM (http://dom.spec.whatwg.org/#dom-nodeiterator-detach).";
 
+    case AttrNodeValue:
+        return "'Attr.nodeValue' is deprecated. Please use 'value' instead.";
+
+    case AttrTextContent:
+        return "'Attr.textContent' is deprecated. Please use 'value' instead.";
+
     // Features that aren't deprecated don't have a deprecation message.
     default:
         return String();