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

Source/modules/vr/VRHardwareUnitCollection.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 VRHardwareUnitCollection_h
 #define VRHardwareUnitCollection_h
 
 #include "modules/vr/VRDevice.h"
 #include "modules/vr/VRHardwareUnit.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/WebVector.h"
 
 namespace blink {
 
 class WebVRDevice;
 
-class VRHardwareUnitCollection final : public RefCountedWillBeGarbageCollected<VRHardwareUnitCollection> {
+class VRHardwareUnitCollection final : public GarbageCollected<VRHardwareUnitCollection> {
 public:
     explicit VRHardwareUnitCollection(VRController*);
 
     VRDeviceVector updateVRHardwareUnits(const WebVector<WebVRDevice>*);
     VRHardwareUnit* getHardwareUnitForIndex(unsigned index);
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
-    PersistentWillBeMember<VRController> m_controller;
-    PersistentHeapVectorWillBeHeapVector<Member<VRHardwareUnit>> m_hardwareUnits;
+    Member<VRController> m_controller;
+    HeapVector<Member<VRHardwareUnit>> m_hardwareUnits;
 };
 
 } // namespace blink
 
 #endif // VRHardwareUnitCollection_h