[VR, Permission] Use appopriate type parameters for WebCallbacks (3/3)

public/platform/modules/vr/WebVRClient.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 WebVRClient_h
 #define WebVRClient_h
 
 #include "public/platform/WebCallbacks.h"
 #include "public/platform/WebVector.h"
 #include "public/platform/modules/vr/WebVR.h"
 
 namespace blink {
 
 // Success and failure callbacks for getDevices.
-class WebVRGetDevicesCallback : public WebCallbacks<const WebVector<WebVRDevice>&, void> {
-public:
-    virtual void onSuccess(const WebVector<WebVRDevice>&) = 0;
-    void onSuccess(WebVector<WebVRDevice>* r) { onSuccess(*r); }
-};
+using WebVRGetDevicesCallback = WebCallbacks<const WebVector<WebVRDevice>&, void>;
 
 // Client handling VR device communication for a given WebFrame.
 class WebVRClient {
 public:
     virtual ~WebVRClient() { }
 
     virtual void getDevices(WebVRGetDevicesCallback*) = 0;
 
     virtual void getSensorState(unsigned index, blink::WebHMDSensorState& into) = 0;
 
     virtual void resetSensor(unsigned index) = 0;
 };
 
 } // namespace blink
 
 #endif // WebVRClient_h