Oilpan: have Navigator and its supplements be on the heap by default.

Source/core/frame/Navigator.h

 /*
     Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 of the License, or (at your option) any later version.
 
     This library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 11 matching lines @@
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "core/frame/DOMWindowProperty.h"
 #include "core/frame/NavigatorCPU.h"
 #include "core/frame/NavigatorID.h"
 #include "core/frame/NavigatorLanguage.h"
 #include "core/frame/NavigatorOnLine.h"
 #include "platform/Supplementable.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Forward.h"
-#include "wtf/PassRefPtr.h"
-#include "wtf/RefCounted.h"
-#include "wtf/RefPtr.h"
 
 namespace blink {
 
 class LocalFrame;
 
 typedef int ExceptionCode;
 
 class Navigator final
-    : public RefCountedWillBeGarbageCollectedFinalized<Navigator>
+    : public GarbageCollectedFinalized<Navigator>
     , public NavigatorCPU
     , public NavigatorID
     , public NavigatorLanguage
     , public NavigatorOnLine
     , public ScriptWrappable
     , public DOMWindowProperty
-    , public WillBeHeapSupplementable<Navigator> {
+    , public HeapSupplementable<Navigator> {
     DEFINE_WRAPPERTYPEINFO();
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(Navigator);
+    USING_GARBAGE_COLLECTED_MIXIN(Navigator);
 public:
-    static PassRefPtrWillBeRawPtr<Navigator> create(LocalFrame* frame)
+    static Navigator* create(LocalFrame* frame)
     {
-        return adoptRefWillBeNoop(new Navigator(frame));
+        return new Navigator(frame);
     }
 
     virtual ~Navigator();
 
     bool cookieEnabled() const;
 
     String productSub() const;
     String vendor() const;
     String vendorSub() const;
 
     virtual String userAgent() const override;
 
     // Relinquishes the storage lock, if one exists.
     void getStorageUpdates();
 
     // NavigatorLanguage
     virtual Vector<String> languages() override;
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     explicit Navigator(LocalFrame*);
 };
 
 } // namespace blink
 
 #endif // Navigator_h