Oilpan: Replace RefPtrs to Node and its subclasses in core/html with Oilpan transitin types.

Source/core/html/HTMLSelectElement.cpp

Index: Source/core/html/HTMLSelectElement.cpp
diff --git a/Source/core/html/HTMLSelectElement.cpp b/Source/core/html/HTMLSelectElement.cpp
index 812d4a447090b56997276d374bf386d1fd0697dd..98423ca129562d96abcaaabceb1bef8c0aebdcd3 100644
--- a/Source/core/html/HTMLSelectElement.cpp
+++ b/Source/core/html/HTMLSelectElement.cpp
@@ -203,7 +203,7 @@ int HTMLSelectElement::activeSelectionEndListIndex() const
 void HTMLSelectElement::add(HTMLElement* element, HTMLElement* before, ExceptionState& exceptionState)
 {
     // Make sure the element is ref'd and deref'd so we don't leak it.
-    RefPtr<HTMLElement> protectNewChild(element);
+    RefPtrWillBeRawPtr<HTMLElement> protectNewChild(element);
 
     if (!element || !(isHTMLOptionElement(element) || isHTMLOptGroupElement(element) || isHTMLHRElement(element)))
         return;
@@ -450,7 +450,7 @@ void HTMLSelectElement::setOption(unsigned index, HTMLOptionElement* option, Exc
     if (index > maxSelectItems - 1)
         index = maxSelectItems - 1;
     int diff = index - length();
-    RefPtr<HTMLElement> before = nullptr;
+    RefPtrWillBeRawPtr<HTMLElement> before = nullptr;
     // Out of array bounds? First insert empty dummies.
     if (diff > 0) {
         setLength(index, exceptionState);