Revert of Move //device/generic_sensor to be part of the internal implementation of the Device Service.

device/generic_sensor/sensor_provider_impl.h

+// Copyright 2016 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 DEVICE_GENERIC_SENSOR_SENSOR_PROVIDER_IMPL_H_
+#define DEVICE_GENERIC_SENSOR_SENSOR_PROVIDER_IMPL_H_
+
+#include "base/macros.h"
+#include "base/single_thread_task_runner.h"
+#include "device/generic_sensor/generic_sensor_export.h"
+#include "device/generic_sensor/public/interfaces/sensor_provider.mojom.h"
+
+namespace device {
+
+class PlatformSensorProvider;
+class PlatformSensor;
+
+// Implementation of SensorProvider mojo interface.
+// Uses PlatformSensorProvider singleton to create platform specific instances
+// of PlatformSensor which are used by SensorImpl.
+class DEVICE_GENERIC_SENSOR_EXPORT SensorProviderImpl final
+    : public mojom::SensorProvider {
+ public:
+  static void Create(
+      scoped_refptr<base::SingleThreadTaskRunner> file_task_runner,
+      mojom::SensorProviderRequest request);
+
+  ~SensorProviderImpl() override;
+
+ private:
+  explicit SensorProviderImpl(PlatformSensorProvider* provider);
+
+  // SensorProvider implementation.
+  void GetSensor(mojom::SensorType type,
+                 mojom::SensorRequest sensor_request,
+                 const GetSensorCallback& callback) override;
+
+  // Helper callback method to return created sensors.
+  void SensorCreated(mojom::SensorType type,
+                     mojo::ScopedSharedBufferHandle cloned_handle,
+                     mojom::SensorRequest sensor_request,
+                     const GetSensorCallback& callback,
+                     scoped_refptr<PlatformSensor> sensor);
+
+  PlatformSensorProvider* provider_;
+  base::WeakPtrFactory<SensorProviderImpl> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(SensorProviderImpl);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_GENERIC_SENSOR_SENSOR_PROVIDER_IMPL_H_