Have NodeList::item() overrides return an Element* when appropriate

Source/core/html/RadioNodeList.cpp

Index: Source/core/html/RadioNodeList.cpp
diff --git a/Source/core/html/RadioNodeList.cpp b/Source/core/html/RadioNodeList.cpp
index c36e4c5bb90a8774a51644a694a8015d6ec0d03c..b40398aefb252b2a973dd78e832219b94171982c 100644
--- a/Source/core/html/RadioNodeList.cpp
+++ b/Source/core/html/RadioNodeList.cpp
@@ -52,12 +52,11 @@ RadioNodeList::~RadioNodeList()
 #endif
 }
 
-static inline HTMLInputElement* toRadioButtonInputElement(Node& node)
+static inline HTMLInputElement* toRadioButtonInputElement(Element& element)
 {
-    ASSERT(node.isElementNode());
-    if (!isHTMLInputElement(node))
+    if (!isHTMLInputElement(element))
         return 0;
-    HTMLInputElement& inputElement = toHTMLInputElement(node);
+    HTMLInputElement& inputElement = toHTMLInputElement(element);
     if (!inputElement.isRadioButton() || inputElement.value().isEmpty())
         return 0;
     return &inputElement;
@@ -67,9 +66,9 @@ String RadioNodeList::value() const
 {
     if (m_onlyMatchImgElements)
         return String();
-    for (unsigned i = 0; i < length(); ++i) {
-        Node* node = item(i);
-        const HTMLInputElement* inputElement = toRadioButtonInputElement(*node);
+    unsigned length = this->length();
+    for (unsigned i = 0; i < length; ++i) {
+        const HTMLInputElement* inputElement = toRadioButtonInputElement(*item(i));
         if (!inputElement || !inputElement->checked())
             continue;
         return inputElement->value();
@@ -81,9 +80,9 @@ void RadioNodeList::setValue(const String& value)
 {
     if (m_onlyMatchImgElements)
         return;
-    for (unsigned i = 0; i < length(); ++i) {
-        Node* node = item(i);
-        HTMLInputElement* inputElement = toRadioButtonInputElement(*node);
+    unsigned length = this->length();
+    for (unsigned i = 0; i < length; ++i) {
+        HTMLInputElement* inputElement = toRadioButtonInputElement(*item(i));
         if (!inputElement || inputElement->value() != value)
             continue;
         inputElement->setChecked(true);