Oilpan: Replace RefPtrs to Node and its subclasses in core/rendering with Oilpan transition types.

Source/core/rendering/RenderTreeAsText.cpp

Index: Source/core/rendering/RenderTreeAsText.cpp
diff --git a/Source/core/rendering/RenderTreeAsText.cpp b/Source/core/rendering/RenderTreeAsText.cpp
index 8bd2c729b1123c12547cf95012c6e57ba334b002..e2a2540893a1a64453ec88865f1550de5db2f505 100644
--- a/Source/core/rendering/RenderTreeAsText.cpp
+++ b/Source/core/rendering/RenderTreeAsText.cpp
@@ -750,7 +750,7 @@ static void writeCounterValuesFromChildren(TextStream& stream, RenderObject* par
 String counterValueForElement(Element* element)
 {
     // Make sure the element is not freed during the layout.
-    RefPtr<Element> elementRef(element);
+    RefPtrWillBeRawPtr<Element> protector(element);
     element->document().updateLayout();
     TextStream stream;
     bool isFirstCounter = true;
@@ -765,7 +765,7 @@ String counterValueForElement(Element* element)
 String markerTextForListItem(Element* element)
 {
     // Make sure the element is not freed during the layout.
-    RefPtr<Element> elementRef(element);
+    RefPtrWillBeRawPtr<Element> protector(element);
     element->document().updateLayout();
 
     RenderObject* renderer = element->renderer();