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

services/device/public/cpp/generic_sensor/sensor_reading.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 SERVICES_DEVICE_PUBLIC_CPP_GENERIC_SENSOR_SENSOR_READING_H_
-#define SERVICES_DEVICE_PUBLIC_CPP_GENERIC_SENSOR_SENSOR_READING_H_
-
-#include "device/base/synchronization/one_writer_seqlock.h"
-#include "services/device/public/interfaces/sensor.mojom.h"
-
-namespace device {
-
-// This class is guarantied to have a fixed size of 64 bits on every platform.
-// It is introduce to simplify sensors shared buffer memory calculation.
-template <typename Data>
-class SensorReadingField {
- public:
-  static_assert(sizeof(Data) <= sizeof(int64_t),
-                "The field size must be <= 64 bits.");
-  SensorReadingField() = default;
-  SensorReadingField(Data value) { storage_.value = value; }
-  SensorReadingField& operator=(Data value) {
-    storage_.value = value;
-    return *this;
-  }
-  Data& value() { return storage_.value; }
-  const Data& value() const { return storage_.value; }
-
-  operator Data() const { return storage_.value; }
-
- private:
-  union Storage {
-    int64_t unused;
-    Data value;
-    Storage() { new (&value) Data(); }
-    ~Storage() { value.~Data(); }
-  };
-  Storage storage_;
-};
-
-// This structure represents sensor reading data: timestamp and 4 values.
-struct SensorReading {
-  SensorReading();
-  ~SensorReading();
-  SensorReading(const SensorReading& other);
-  SensorReadingField<double> timestamp;
-  constexpr static int kValuesCount = 4;
-  // AMBIENT_LIGHT:
-  // values[0]: ambient light level in SI lux units.
-  //
-  // PROXIMITY:
-  // values[0]: proximity sensor distance measured in centimeters.
-  //
-  // ACCELEROMETER:
-  // values[0]: acceleration minus Gx on the x-axis.
-  // values[1]: acceleration minus Gy on the y-axis.
-  // values[2]: acceleration minus Gz on the z-axis.
-  //
-  // LINEAR_ACCELERATION:
-  // values[0]: acceleration on the x-axis.
-  // values[1]: acceleration on the y-axis.
-  // values[2]: acceleration on the z-axis.
-  //
-  // GYROSCOPE:
-  // values[0]: angular speed around the x-axis.
-  // values[1]: angular speed around the y-axis.
-  // values[2]: angular speed around the z-axis.
-  //
-  // MAGNETOMETER:
-  // values[0]: ambient magnetic field in the x-axis in micro-Tesla (uT).
-  // values[1]: ambient magnetic field in the y-axis in micro-Tesla (uT).
-  // values[2]: ambient magnetic field in the z-axis in micro-Tesla (uT).
-  //
-  // PRESSURE:
-  // values[0]: atmospheric pressure in hPa (millibar).
-  //
-  // ABSOLUTE_ORIENTATION:
-  // values[0]: x value of a quaternion representing the orientation of the
-  // device in 3D space.
-  // values[1]: y value of a quaternion representing the orientation of the
-  // device in 3D space.
-  // values[2]: z value of a quaternion representing the orientation of the
-  // device in 3D space.
-  // values[3]: w value of a quaternion representing the orientation of the
-  // device in 3D space.
-  //
-  // RELATIVE_ORIENTATION:
-  // (Identical to ABSOLUTE_ORIENTATION except that it doesn't use the
-  // geomagnetic field.)
-  // values[0]: x value of a quaternion representing the orientation of the
-  // device in 3D space.
-  // values[1]: y value of a quaternion representing the orientation of the
-  // device in 3D space.
-  // values[2]: z value of a quaternion representing the orientation of the
-  // device in 3D space.
-  // values[3]: w value of a quaternion representing the orientation of the
-  // device in 3D space.
-  SensorReadingField<double> values[kValuesCount];
-};
-
-// This structure represents sensor reading buffer: sensor reading and seqlock
-// for synchronization.
-struct SensorReadingSharedBuffer {
-  SensorReadingSharedBuffer();
-  ~SensorReadingSharedBuffer();
-  SensorReadingField<OneWriterSeqLock> seqlock;
-  SensorReading reading;
-
-  // Gets the shared reading buffer offset for the given sensor type.
-  static uint64_t GetOffset(mojom::SensorType type);
-};
-
-}  // namespace device
-
-#endif  // SERVICES_DEVICE_PUBLIC_CPP_GENERIC_SENSOR_SENSOR_READING_H_