[sensors] Introduce Generic Sensor API interfaces

device/sensors/mojo/sensor_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_SENSORS_MOJO_SENSOR_IMPL_H_
+#define DEVICE_SENSORS_MOJO_SENSOR_IMPL_H_
+
+#include "base/macros.h"
+#include "device/sensors/platform/platform_sensor.h"
+#include "device/sensors/public/interfaces/sensor.mojom.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+
+namespace device {
+
+namespace sensors {
+
+// Implementation of Sensor mojo interface.
+// Instances of this class are created by SensorFactoryImpl.
+class SensorImpl final : public Sensor, public device::PlatformSensor::Client {
+ public:
+  SensorImpl(mojo::InterfaceRequest<Sensor> request,
+             scoped_refptr<device::PlatformSensor> sensor);
+  ~SensorImpl() override;
+
+ private:
+  // Sensor implementation.
+  void SetClient(SensorClientPtr client) override;
+  void Start(SensorConfigurationPtr configuration,
+             const StartCallback& callback) override;
+  void Stop(SensorConfigurationPtr configuration,
+            const StopCallback& callback) override;
+
+  // device::Sensor::Client implementation.
+  void OnSensorReadingChanged() override;
+  void OnSensorError() override;
+
+ private:
+  scoped_refptr<device::PlatformSensor> sensor_;
+  mojo::StrongBinding<Sensor> binding_;
+  SensorClientPtr client_;
+  DISALLOW_COPY_AND_ASSIGN(SensorImpl);
+};
+
+}  // namespace sensors
+}  // namespace device
+
+#endif  // DEVICE_SENSORS_MOJO_SENSOR_IMPL_H_