Oilpan: Prepare to move AXObjectCache to the heap

Source/core/dom/Element.cpp

Index: Source/core/dom/Element.cpp
diff --git a/Source/core/dom/Element.cpp b/Source/core/dom/Element.cpp
index c2db12d8bc29a05037ba8dc3090e5c7f3f18da23..09a8e2d13dde841e6fc8af27a9ee533fcb7e79fc 100644
--- a/Source/core/dom/Element.cpp
+++ b/Source/core/dom/Element.cpp
@@ -998,15 +998,15 @@ IntRect Element::screenRect() const
 const AtomicString& Element::computedRole()
 {
     document().updateLayoutIgnorePendingStylesheets();
-    RefPtr<ScopedAXObjectCache> cache(adoptRef(new ScopedAXObjectCache(document())));
-    return (*cache)->computedRoleForNode(this);
+    OwnPtr<ScopedAXObjectCache> cache = ScopedAXObjectCache::create(document());
+    return cache->get()->computedRoleForNode(this);
 }
 
 String Element::computedName()
 {
     document().updateLayoutIgnorePendingStylesheets();
-    RefPtr<ScopedAXObjectCache> cache(adoptRef(new ScopedAXObjectCache(document())));
-    return (*cache)->computedNameForNode(this);
+    OwnPtr<ScopedAXObjectCache> cache = ScopedAXObjectCache::create(document());
+    return cache->get()->computedNameForNode(this);
 }
 
 const AtomicString& Element::getAttribute(const AtomicString& localName) const