Oilpan: Prepare moving AXObject to heap

Source/modules/accessibility/AXListBox.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 32 matching lines @@
     : AXLayoutObject(layoutObject, axObjectCache)
     , m_activeIndex(-1)
 {
     activeIndexChanged();
 }
 
 AXListBox::~AXListBox()
 {
 }
 
-PassRefPtr<AXListBox> AXListBox::create(LayoutObject* layoutObject, AXObjectCacheImpl& axObjectCache)
+PassRefPtrWillBeRawPtr<AXListBox> AXListBox::create(LayoutObject* layoutObject, AXObjectCacheImpl& axObjectCache)
 {
-    return adoptRef(new AXListBox(layoutObject, axObjectCache));
+    return adoptRefWillBeNoop(new AXListBox(layoutObject, axObjectCache));
 }
 
 AccessibilityRole AXListBox::determineAccessibilityRole()
 {
     if ((m_ariaRole = determineAriaRoleAttribute()) != UnknownRole)
         return m_ariaRole;
 
     return ListBoxRole;
 }
 
@@ skipping 28 matching lines @@
 
     if (m_activeIndex >= 0 && m_activeIndex < static_cast<int>(select->length())) {
         HTMLOptionElement* option = select->item(m_activeIndex);
         axObjectCache().postNotification(option, AXObjectCacheImpl::AXFocusedUIElementChanged);
     } else {
         axObjectCache().postNotification(this, AXObjectCacheImpl::AXFocusedUIElementChanged);
     }
 }
 
 } // namespace blink