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

Source/core/html/forms/TextFieldInputType.cpp

Index: Source/core/html/forms/TextFieldInputType.cpp
diff --git a/Source/core/html/forms/TextFieldInputType.cpp b/Source/core/html/forms/TextFieldInputType.cpp
index f10c398f13a65840e1537fcfa0ca51b9cc90be14..8a345ea0b014d108b1165bdcc4b74601f1938711 100644
--- a/Source/core/html/forms/TextFieldInputType.cpp
+++ b/Source/core/html/forms/TextFieldInputType.cpp
@@ -457,7 +457,7 @@ void TextFieldInputType::updatePlaceholderText()
         return;
     }
     if (!placeholder) {
-        RefPtr<HTMLElement> newElement = HTMLDivElement::create(element().document());
+        RefPtrWillBeRawPtr<HTMLElement> newElement = HTMLDivElement::create(element().document());
         placeholder = newElement.get();
         placeholder->setShadowPseudoId(AtomicString("-webkit-input-placeholder", AtomicString::ConstructFromLiteral));
         placeholder->setAttribute(idAttr, ShadowElementNames::placeholder());