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

services/device/generic_sensor/platform_sensor_reader_linux.cc

-// 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.
-
-#include "services/device/generic_sensor/platform_sensor_reader_linux.h"
-
-#include "base/files/file_util.h"
-#include "base/memory/ptr_util.h"
-#include "base/single_thread_task_runner.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/strings/string_util.h"
-#include "base/threading/thread_restrictions.h"
-#include "base/timer/timer.h"
-#include "services/device/generic_sensor/linux/sensor_data_linux.h"
-#include "services/device/generic_sensor/platform_sensor_linux.h"
-#include "services/device/public/cpp/generic_sensor/sensor_reading.h"
-
-namespace device {
-
-class PollingSensorReader : public SensorReader {
- public:
-  PollingSensorReader(const SensorInfoLinux* sensor_device,
-                      base::WeakPtr<PlatformSensorLinux> sensor,
-                      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
-  ~PollingSensorReader() override;
-
-  // SensorReader implements:
-  void StartFetchingData(
-      const PlatformSensorConfiguration& configuration) override;
-  void StopFetchingData() override;
-
- private:
-  // Initializes a read timer.
-  void InitializeTimer(const PlatformSensorConfiguration& configuration);
-
-  // Polls data and sends it to a |sensor_|.
-  void PollForData();
-
-  // Paths to sensor read files.
-  const std::vector<base::FilePath> sensor_file_paths_;
-
-  // Scaling value that are applied to raw data from sensors.
-  const double scaling_value_;
-
-  // Offset value.
-  const double offset_value_;
-
-  // Used to apply scalings and invert signs if needed.
-  const SensorPathsLinux::ReaderFunctor apply_scaling_func_;
-
-  // Repeating timer for data polling.
-  base::RepeatingTimer timer_;
-
-  DISALLOW_COPY_AND_ASSIGN(PollingSensorReader);
-};
-
-PollingSensorReader::PollingSensorReader(
-    const SensorInfoLinux* sensor_device,
-    base::WeakPtr<PlatformSensorLinux> sensor,
-    scoped_refptr<base::SingleThreadTaskRunner> task_runner)
-    : SensorReader(sensor, std::move(task_runner)),
-      sensor_file_paths_(sensor_device->device_reading_files),
-      scaling_value_(sensor_device->device_scaling_value),
-      offset_value_(sensor_device->device_offset_value),
-      apply_scaling_func_(sensor_device->apply_scaling_func) {}
-
-PollingSensorReader::~PollingSensorReader() {
-  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
-}
-
-void PollingSensorReader::StartFetchingData(
-    const PlatformSensorConfiguration& configuration) {
-  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
-  if (is_reading_active_)
-    StopFetchingData();
-  InitializeTimer(configuration);
-}
-
-void PollingSensorReader::StopFetchingData() {
-  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
-  is_reading_active_ = false;
-  timer_.Stop();
-}
-
-void PollingSensorReader::InitializeTimer(
-    const PlatformSensorConfiguration& configuration) {
-  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
-  DCHECK(!is_reading_active_);
-  timer_.Start(
-      FROM_HERE,
-      base::TimeDelta::FromMicroseconds(base::Time::kMicrosecondsPerSecond /
-                                        configuration.frequency()),
-      this, &PollingSensorReader::PollForData);
-  is_reading_active_ = true;
-}
-
-void PollingSensorReader::PollForData() {
-  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
-
-  SensorReading readings;
-  DCHECK_LE(sensor_file_paths_.size(), arraysize(readings.values));
-  int i = 0;
-  for (const auto& path : sensor_file_paths_) {
-    std::string new_read_value;
-    if (!base::ReadFileToString(path, &new_read_value)) {
-      NotifyReadError();
-      StopFetchingData();
-      return;
-    }
-
-    double new_value = 0;
-    base::TrimWhitespaceASCII(new_read_value, base::TRIM_ALL, &new_read_value);
-    if (!base::StringToDouble(new_read_value, &new_value)) {
-      NotifyReadError();
-      StopFetchingData();
-      return;
-    }
-    readings.values[i++] = new_value;
-  }
-  if (!apply_scaling_func_.is_null())
-    apply_scaling_func_.Run(scaling_value_, offset_value_, readings);
-
-  if (is_reading_active_) {
-    task_runner_->PostTask(
-        FROM_HERE, base::Bind(&PlatformSensorLinux::UpdatePlatformSensorReading,
-                              sensor_, readings));
-  }
-}
-
-// static
-std::unique_ptr<SensorReader> SensorReader::Create(
-    const SensorInfoLinux* sensor_device,
-    base::WeakPtr<PlatformSensorLinux> sensor,
-    scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
-  base::ThreadRestrictions::AssertIOAllowed();
-  // TODO(maksims): implement triggered reading. At the moment,
-  // only polling read is supported.
-  return base::MakeUnique<PollingSensorReader>(sensor_device, sensor,
-                                               std::move(task_runner));
-}
-
-SensorReader::SensorReader(
-    base::WeakPtr<PlatformSensorLinux> sensor,
-    scoped_refptr<base::SingleThreadTaskRunner> task_runner)
-    : sensor_(sensor),
-      task_runner_(std::move(task_runner)),
-      is_reading_active_(false) {
-  DETACH_FROM_THREAD(thread_checker_);
-}
-
-SensorReader::~SensorReader() {
-  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
-}
-
-void SensorReader::NotifyReadError() {
-  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
-  if (is_reading_active_) {
-    task_runner_->PostTask(
-        FROM_HERE,
-        base::Bind(&PlatformSensorLinux::NotifyPlatformSensorError, sensor_));
-  }
-}
-
-}  // namespace device