Clarify comments for methods added in r178921

Source/core/dom/Element.h

Index: Source/core/dom/Element.h
diff --git a/Source/core/dom/Element.h b/Source/core/dom/Element.h
index f2c5a9d8f998a346a637c7ab6466954822286e3f..74374e31d1db4983063198aeaf1984cc3aab21ee 100644
--- a/Source/core/dom/Element.h
+++ b/Source/core/dom/Element.h
@@ -561,9 +561,9 @@ private:
     void clearElementFlag(ElementFlags);
     bool hasElementFlagInternal(ElementFlags) const;
 
-    bool isElementNode() const WTF_DELETED_FUNCTION; // Hide to catch useless calls.
-    bool isDocumentFragment() const WTF_DELETED_FUNCTION; // Hide to catch useless calls.
-    bool isDocumentNode() const WTF_DELETED_FUNCTION; // Hide to catch useless calls.
+    bool isElementNode() const WTF_DELETED_FUNCTION; // This will catch anyone doing an unnecessary check.
+    bool isDocumentFragment() const WTF_DELETED_FUNCTION; // This will catch anyone doing an unnecessary check.
+    bool isDocumentNode() const WTF_DELETED_FUNCTION; // This will catch anyone doing an unnecessary check.
 
     void styleAttributeChanged(const AtomicString& newStyleString, AttributeModificationReason);