sensors: Remove prototype implementation

content/browser/sensors/sensors_provider_impl.h

-// Copyright (c) 2012 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 CONTENT_BROWSER_SENSORS_SENSORS_PROVIDER_IMPL_H_
-#define CONTENT_BROWSER_SENSORS_SENSORS_PROVIDER_IMPL_H_
-#pragma once
-
-#include "base/compiler_specific.h"
-#include "base/memory/ref_counted.h"
-#include "base/observer_list_threadsafe.h"
-#include "content/public/browser/sensors_provider.h"
-
-template <typename T> struct DefaultSingletonTraits;
-
-namespace content {
-
-class SensorsProviderImpl : public SensorsProvider {
- public:
-  static SensorsProviderImpl* GetInstance();
-
-  // SensorsProvider implementation:
-  virtual void AddListener(SensorsListener* listener) OVERRIDE;
-  virtual void RemoveListener(SensorsListener* listener) OVERRIDE;
-  virtual void ScreenOrientationChanged(ScreenOrientation change) OVERRIDE;
-
- private:
-  friend struct DefaultSingletonTraits<SensorsProviderImpl>;
-
-  SensorsProviderImpl();
-  virtual ~SensorsProviderImpl();
-
-  typedef ObserverListThreadSafe<SensorsListener> ListenerList;
-  scoped_refptr<ListenerList> listeners_;
-
-  DISALLOW_COPY_AND_ASSIGN(SensorsProviderImpl);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_SENSORS_SENSORS_PROVIDER_IMPL_H_