Migrate vr to use inlined tracing

Source/modules/vr/HMDVRDevice.cpp

 // 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.
 
 #include "config.h"
 #include "modules/vr/HMDVRDevice.h"
 
 #include "modules/vr/VRFieldOfView.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebSize.h"
@@ skipping 68 matching lines @@
 
     if (rightFov) {
         hardwareUnit()->setFieldOfView(VREyeRight, rightFov);
         m_eyeParametersLeft->setCurrentFieldOfView(rightFov);
     } else {
         hardwareUnit()->setFieldOfView(VREyeRight, m_eyeParametersRight->recommendedFieldOfView());
         m_eyeParametersRight->setCurrentFieldOfView(m_eyeParametersRight->recommendedFieldOfView());
     }
 }
 
-void HMDVRDevice::trace(Visitor* visitor)
+DEFINE_TRACE(HMDVRDevice)
 {
     visitor->trace(m_eyeParametersLeft);
     visitor->trace(m_eyeParametersRight);
 
     VRDevice::trace(visitor);
 }
 
 } // namespace blink