Migrate vr to use inlined tracing

Source/modules/vr/VRPositionState.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/VRPositionState.h"
 
 namespace blink {
 
 namespace {
@@ skipping 22 matching lines @@
 {
     m_timeStamp = state.timestamp;
     m_orientation = VecToDomPoint(state.orientation, state.flags & WebVRSensorStateOrientation);
     m_position = VecToDomPoint(state.position, state.flags & WebVRSensorStatePosition);
     m_angularVelocity = VecToDomPoint(state.angularVelocity, state.flags & WebVRSensorStateAngularVelocity);
     m_linearVelocity = VecToDomPoint(state.linearVelocity, state.flags & WebVRSensorStateLinearVelocity);
     m_angularAcceleration = VecToDomPoint(state.angularAcceleration, state.flags & WebVRSensorStateAngularAcceleration);
     m_linearAcceleration =  VecToDomPoint(state.linearAcceleration, state.flags & WebVRSensorStateLinearAcceleration);
 }
 
-void VRPositionState::trace(Visitor* visitor)
+DEFINE_TRACE(VRPositionState)
 {
     visitor->trace(m_orientation);
     visitor->trace(m_position);
     visitor->trace(m_angularVelocity);
     visitor->trace(m_linearVelocity);
     visitor->trace(m_angularAcceleration);
     visitor->trace(m_linearAcceleration);
 }
 
 } // namespace blink