Migrate vr to use inlined tracing

Source/modules/vr/HMDVRDevice.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 HMDVRDevice_h
 #define HMDVRDevice_h
 
 #include "modules/vr/VRDevice.h"
 #include "modules/vr/VREyeParameters.h"
 #include "platform/heap/Handle.h"
@@ skipping 12 matching lines @@
 public:
     explicit HMDVRDevice(VRHardwareUnit*);
 
     typedef Vector<double> DoubleVector;
 
     virtual void updateFromWebVRDevice(const WebVRDevice&) override;
 
     VREyeParameters* getEyeParameters(const String&);
     void setFieldOfView(VRFieldOfView* leftFov = 0, VRFieldOfView* rightFov = 0);
 
-    virtual void trace(Visitor*) override;
+    DECLARE_VIRTUAL_TRACE();
 
 private:
     static VREye StringToVREye(const String&);
 
     Member<VREyeParameters> m_eyeParametersLeft;
     Member<VREyeParameters> m_eyeParametersRight;
     bool m_dirtyFov;
 };
 
 } // namespace blink
 
 #endif // HMDVRDevice_h