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

Source/modules/plugins/NavigatorPlugins.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NavigatorPlugins_h
 #define NavigatorPlugins_h
 
 #include "core/frame/DOMWindowProperty.h"
 #include "platform/Supplementable.h"
 
 namespace blink {
 
 class DOMMimeTypeArray;
 class DOMPluginArray;
 class LocalFrame;
 class Navigator;
 
-class NavigatorPlugins final
-    : public NoBaseWillBeGarbageCollected<NavigatorPlugins>
-    , public WillBeHeapSupplement<Navigator>
-    , DOMWindowProperty {
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(NavigatorPlugins);
-    DECLARE_EMPTY_VIRTUAL_DESTRUCTOR_WILL_BE_REMOVED(NavigatorPlugins);
+// TODO(Oilpan): when ~DOMWindowProperty is removed, derive from GarbageCollected<> instead.
+class NavigatorPlugins final : public GarbageCollectedFinalized<NavigatorPlugins>, public HeapSupplement<Navigator>, DOMWindowProperty {
+    USING_GARBAGE_COLLECTED_MIXIN(NavigatorPlugins);
 public:
     static NavigatorPlugins& from(Navigator&);
     static NavigatorPlugins* toNavigatorPlugins(Navigator&);
-    static const char* supplementName();
+
+    virtual ~NavigatorPlugins();
 
     static DOMPluginArray* plugins(Navigator&);
     static DOMMimeTypeArray* mimeTypes(Navigator&);
     static bool javaEnabled(Navigator&);
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     explicit NavigatorPlugins(Navigator&);
 
+    static const char* supplementName();
+
     DOMPluginArray* plugins(LocalFrame*) const;
     DOMMimeTypeArray* mimeTypes(LocalFrame*) const;
     bool javaEnabled(LocalFrame*) const;
 
     mutable RefPtrWillBeMember<DOMPluginArray> m_plugins;
     mutable RefPtrWillBeMember<DOMMimeTypeArray> m_mimeTypes;
 };
 
 } // namespace blink
 
 #endif // NavigatorPlugins_h