Oilpan: add Element/Node Member fields to stack allocated objects.

Source/core/dom/RenderTreeBuilder.h

Index: Source/core/dom/RenderTreeBuilder.h
diff --git a/Source/core/dom/RenderTreeBuilder.h b/Source/core/dom/RenderTreeBuilder.h
index 3a98514224c236da5ecff5b1d71c0e2c006ce256..b92b1af8a94cf2f67ce77aa7b3b67dbf2eba755d 100644
--- a/Source/core/dom/RenderTreeBuilder.h
+++ b/Source/core/dom/RenderTreeBuilder.h
@@ -38,10 +38,11 @@ class RenderObject;
 class RenderStyle;
 
 class RenderTreeBuilder {
+    STACK_ALLOCATED();
 public:
     RenderTreeBuilder(Node* node, RenderStyle* style)
         : m_node(node)
-        , m_renderingParent(0)
+        , m_renderingParent(nullptr)
         , m_style(style)
     {
         ASSERT(!node->renderer());
@@ -66,8 +67,8 @@ private:
     bool shouldCreateRenderer() const;
     RenderStyle& style() const;
 
-    Node* m_node;
-    ContainerNode* m_renderingParent;
+    RawPtrWillBeMember<Node> m_node;
+    RawPtrWillBeMember<ContainerNode> m_renderingParent;
     NodeRenderingTraversal::ParentDetails m_parentDetails;
     mutable RefPtr<RenderStyle> m_style;
 };