Move //device/sensor impl to be part of the internal implemenation of the Device Service.

device/sensors/device_sensor_service.h

-// Copyright 2014 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_DEVICE_SENSOR_SERVICE_H_
-#define DEVICE_SENSORS_DEVICE_SENSOR_SERVICE_H_
-
-#include <memory>
-
-#include "base/callback_forward.h"
-#include "base/macros.h"
-#include "base/memory/shared_memory.h"
-#include "base/memory/singleton.h"
-#include "base/message_loop/message_loop.h"
-#include "base/threading/thread_checker.h"
-#include "device/sensors/device_sensor_export.h"
-#include "device/sensors/device_sensors_consts.h"
-#include "mojo/public/cpp/system/buffer.h"
-
-namespace device {
-
-class DataFetcherSharedMemory;
-
-// Owns the data fetcher for Device Motion and Orientation and keeps track of
-// the number of consumers currently using the data. The data fetcher is stopped
-// when there are no consumers.
-class DEVICE_SENSOR_EXPORT DeviceSensorService
-    : public base::MessageLoop::DestructionObserver {
- public:
-  // Returns the DeviceSensorService singleton.
-  static DeviceSensorService* GetInstance();
-
-  // Increments the number of users of the provider. The Provider is running
-  // when there's > 0 users, and is paused when the count drops to 0.
-  // Must be called on the I/O thread.
-  void AddConsumer(ConsumerType consumer_type);
-
-  // Removes a consumer. Should be matched with an AddConsumer call.
-  // Must be called on the I/O thread.
-  void RemoveConsumer(ConsumerType cosumer_type);
-
-  // Returns the shared memory handle of the device motion data.
-  mojo::ScopedSharedBufferHandle GetSharedMemoryHandle(
-      ConsumerType consumer_type);
-
-  // base::MessageLoop::DestructionObserver:
-  void WillDestroyCurrentMessageLoop() override;
-
-  // Stop/join with the background polling thread in |provider_|.
-  void Shutdown();
-
-  // Injects a custom data fetcher for testing purposes. This class takes
-  // ownership of the injected object.
-  void SetDataFetcherForTesting(DataFetcherSharedMemory* test_data_fetcher);
-
- private:
-  friend struct base::DefaultSingletonTraits<DeviceSensorService>;
-
-  DeviceSensorService();
-  ~DeviceSensorService() override;
-
-  bool ChangeNumberConsumers(ConsumerType consumer_type, int delta);
-  int GetNumberConsumers(ConsumerType consumer_type) const;
-
-  int num_light_readers_;
-  int num_motion_readers_;
-  int num_orientation_readers_;
-  int num_orientation_absolute_readers_;
-  bool is_shutdown_;
-  std::unique_ptr<DataFetcherSharedMemory> data_fetcher_;
-  base::ThreadChecker thread_checker_;
-
-  DISALLOW_COPY_AND_ASSIGN(DeviceSensorService);
-};
-
-}  // namespace device
-
-#endif  // DEVICE_SENSORS_DEVICE_SENSOR_SERVICE_H_