Migrate vr to use inlined tracing

Source/modules/vr/NavigatorVRDevice.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 NavigatorVRDevice_h
 #define NavigatorVRDevice_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "modules/vr/VRDevice.h"
 #include "modules/vr/VRHardwareUnit.h"
 #include "platform/Supplementable.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class Document;
 class Navigator;
 
 class NavigatorVRDevice final : public NoBaseWillBeGarbageCollectedFinalized<NavigatorVRDevice>, public WillBeHeapSupplement<Navigator> {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(NavigatorVRDevice);
 public:
     static NavigatorVRDevice* from(Document&);
     static NavigatorVRDevice& from(Navigator&);
     virtual ~NavigatorVRDevice();
 
     static ScriptPromise getVRDevices(ScriptState*, Navigator&);
     ScriptPromise getVRDevices(ScriptState*);
 
-    virtual void trace(Visitor*);
+    DECLARE_VIRTUAL_TRACE();
 
 private:
     friend VRHardwareUnit;
 
     NavigatorVRDevice();
 
     static const char* supplementName();
 
     VRDeviceVector getUpdatedVRHardwareUnits();
     VRHardwareUnit* getHardwareUnitForIndex(unsigned index);
 
     PersistentHeapVectorWillBeHeapVector<Member<VRHardwareUnit>> m_hardwareUnits;
 };
 
 } // namespace blink
 
 #endif // NavigatorVRDevice_h