Use isHTMLTextAreaElement and toHTMLTextAreaElement

Source/core/html/HTMLTextAreaElement.h

Index: Source/core/html/HTMLTextAreaElement.h
diff --git a/Source/core/html/HTMLTextAreaElement.h b/Source/core/html/HTMLTextAreaElement.h
index 93970e47182201dad73e235d87b8afeeb4de3cef..58808aa0da78a6aadf03e32ecb9bc2078c395cf0 100644
--- a/Source/core/html/HTMLTextAreaElement.h
+++ b/Source/core/html/HTMLTextAreaElement.h
@@ -127,11 +127,16 @@ private:
     mutable bool m_wasModifiedByUser;
 };
 
-inline bool isHTMLTextAreaElement(Node* node)
+inline bool isHTMLTextAreaElement(const Node* node)
 {
     return node->hasTagName(HTMLNames::textareaTag);
 }
 
+inline bool isHTMLTextAreaElement(const Element* element)
+{
+    return element->hasTagName(HTMLNames::textareaTag);
+}
+
 inline HTMLTextAreaElement* toHTMLTextAreaElement(Node* node)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!node || isHTMLTextAreaElement(node));